diff --git a/src/logid/Configuration.h b/src/logid/Configuration.h
index 5c90974..621f0bd 100644
--- a/src/logid/Configuration.h
+++ b/src/logid/Configuration.h
@@ -30,7 +30,7 @@
 
 namespace logid {
     namespace defaults {
-        static constexpr double io_timeout = 500;
+        static constexpr double io_timeout = 1000;
         static constexpr int gesture_threshold = 50;
     }
 
diff --git a/src/logid/backend/hidpp/Device.cpp b/src/logid/backend/hidpp/Device.cpp
index eb61dd2..96472e2 100644
--- a/src/logid/backend/hidpp/Device.cpp
+++ b/src/logid/backend/hidpp/Device.cpp
@@ -51,10 +51,10 @@ Device::InvalidDevice::Reason Device::InvalidDevice::code() const noexcept {
 }
 
 Device::Device(const std::string& path, DeviceIndex index,
-               std::shared_ptr<raw::DeviceMonitor> monitor, double timeout) :
+               const std::shared_ptr<raw::DeviceMonitor>& monitor, double timeout) :
         io_timeout(duration_cast<milliseconds>(
                 duration<double, std::milli>(timeout))),
-        _raw_device(std::make_shared<raw::RawDevice>(path, std::move(monitor))),
+        _raw_device(std::make_shared<raw::RawDevice>(path, monitor)),
         _receiver(nullptr), _path(path), _index(index) {
     _init();
 }
@@ -133,7 +133,7 @@ void Device::_init() {
             auto rsp = sendReport(
                     {ReportType::Short, _index,
                      hidpp20::FeatureID::ROOT, hidpp20::Root::Ping,
-                     LOGID_HIDPP_SOFTWARE_ID});
+                     hidpp::softwareID});
             if (rsp.deviceIndex() != _index) {
                 throw InvalidDevice(InvalidDevice::VirtualNode);
             }
@@ -152,12 +152,9 @@ void Device::_init() {
 
                     [index = this->_index](
                             const std::vector<uint8_t>& report) -> bool {
-                        return (report[Offset::Type] ==
-                                Report::Type::Short ||
-                                report[Offset::Type] ==
-                                Report::Type::Long) &&
-                               (report[Offset::DeviceIndex] ==
-                                index);
+                        return (report[Offset::Type] == Report::Type::Short ||
+                                report[Offset::Type] == Report::Type::Long) &&
+                               (report[Offset::DeviceIndex] == index);
                     },
                     [this](const std::vector<uint8_t>& report) -> void {
                         Report _report(report);
@@ -212,13 +209,13 @@ Device::~Device() {
 }
 
 Device::EvHandlerId Device::addEventHandler(EventHandler handler) {
-    std::lock_guard<std::mutex> lock(_event_handler_lock);
+    std::unique_lock lock(_event_handler_mutex);
     _event_handlers.emplace_front(std::move(handler));
     return _event_handlers.cbegin();
 }
 
 void Device::removeEventHandler(EvHandlerId id) {
-    std::lock_guard<std::mutex> lock(_event_handler_lock);
+    std::unique_lock lock(_event_handler_mutex);
     _event_handlers.erase(id);
 }
 
@@ -226,66 +223,82 @@ void Device::handleEvent(Report& report) {
     if (responseReport(report))
         return;
 
-    std::lock_guard<std::mutex> lock(_event_handler_lock);
+    std::shared_lock lock(_event_handler_mutex);
     for (auto& handler: _event_handlers)
         if (handler.condition(report))
             handler.callback(report);
 }
 
 Report Device::sendReport(const Report& report) {
-    std::lock_guard<std::mutex> lock(_send_lock);
-    {
-        std::lock_guard<std::mutex> sl(_slot_lock);
-        _report_slot = {};
-    }
-    sendReportNoResponse(report);
-    std::unique_lock<std::mutex> wait(_resp_wait_lock);
-    bool valid = _resp_cv.wait_for(
-            wait, io_timeout, [this]() {
-                std::lock_guard<std::mutex> sl(_slot_lock);
-                return _report_slot.has_value();
+    /* Must complete transaction before next send */
+    std::lock_guard send_lock(_send_mutex);
+    _sent_sub_id = report.subId();
+    std::unique_lock lock(_response_mutex);
+    _sendReport(report);
+
+    bool valid = _response_cv.wait_for(
+            lock, io_timeout, [this]() {
+                return _response.has_value();
             });
 
-    if (!valid)
+    if (!valid) {
+        _sent_sub_id.reset();
         throw TimeoutError();
-
-    std::lock_guard<std::mutex> sl(_slot_lock);
-
-    {
-        Report::Hidpp10Error error{};
-        if (_report_slot.value().isError10(&error))
-            throw hidpp10::Error(error.error_code);
     }
-    {
-        Report::Hidpp20Error error{};
-        if (_report_slot.value().isError20(&error))
-            throw hidpp20::Error(error.error_code);
+
+    Response response = _response.value();
+    _response.reset();
+    _sent_sub_id.reset();
+
+    if (std::holds_alternative<Report>(response)) {
+        return std::get<Report>(response);
+    } else if(std::holds_alternative<Report::Hidpp10Error>(response)) {
+        throw hidpp20::Error(std::get<Report::Hidpp10Error>(response).error_code);
+    } else if(std::holds_alternative<Report::Hidpp20Error>(response)) {
+        throw hidpp20::Error(std::get<Report::Hidpp20Error>(response).error_code);
     }
-    return _report_slot.value();
+
+    // Should not be reached
+    throw std::runtime_error("unhandled variant type");
 }
 
 bool Device::responseReport(const Report& report) {
-    if (_send_lock.try_lock()) {
-        _send_lock.unlock();
+    std::lock_guard lock(_response_mutex);
+    Response response = report;
+    uint8_t sub_id;
+
+    Report::Hidpp10Error hidpp10_error{};
+    Report::Hidpp20Error hidpp20_error{};
+    if (report.isError10(&hidpp10_error)) {
+        sub_id = hidpp10_error.sub_id;
+        response = hidpp10_error;
+    } else if (report.isError20(&hidpp20_error)) {
+        sub_id = hidpp20_error.feature_index;
+        response = hidpp20_error;
+    } else {
+        sub_id = report.subId();
+    }
+
+    if (sub_id == _sent_sub_id) {
+        _response = response;
+        _response_cv.notify_all();
+        return true;
+    } else {
         return false;
     }
 
-    // Basic check to see if the report is a response
-    if ((report.swId() != LOGID_HIDPP_SOFTWARE_ID)
-        && report.subId() < 0x80)
-        return false;
-
-    std::lock_guard lock(_slot_lock);
-    _report_slot = report;
-    _resp_cv.notify_all();
-    return true;
 }
 
-void Device::sendReportNoResponse(Report report) {
+void Device::_sendReport(Report report) {
     reportFixup(report);
     _raw_device->sendReport(report.rawReport());
 }
 
+void Device::sendReportNoACK(const Report& report) {
+    std::lock_guard lock(_send_mutex);
+    _sendReport(report);
+}
+
 void Device::reportFixup(Report& report) const {
     switch (report.type()) {
         case Report::Type::Short:
diff --git a/src/logid/backend/hidpp/Device.h b/src/logid/backend/hidpp/Device.h
index 8976203..9536a73 100644
--- a/src/logid/backend/hidpp/Device.h
+++ b/src/logid/backend/hidpp/Device.h
@@ -20,6 +20,7 @@
 #define LOGID_BACKEND_HIDPP_DEVICE_H
 
 #include <optional>
+#include <variant>
 #include <string>
 #include <memory>
 #include <functional>
@@ -64,7 +65,7 @@ namespace logid::backend::hidpp {
         };
 
         Device(const std::string& path, DeviceIndex index,
-               std::shared_ptr<raw::DeviceMonitor> monitor, double timeout);
+               const std::shared_ptr<raw::DeviceMonitor>& monitor, double timeout);
 
         Device(std::shared_ptr<raw::RawDevice> raw_device, DeviceIndex index,
                double timeout);
@@ -93,7 +94,7 @@ namespace logid::backend::hidpp {
 
         virtual Report sendReport(const Report& report);
 
-        void sendReportNoResponse(Report report);
+        virtual void sendReportNoACK(const Report& report);
 
         void handleEvent(Report& report);
 
@@ -101,10 +102,15 @@ namespace logid::backend::hidpp {
         // Returns whether the report is a response
         virtual bool responseReport(const Report& report);
 
+        void _sendReport(Report report);
+
         void reportFixup(Report& report) const;
 
         const std::chrono::milliseconds io_timeout;
-        uint8_t supported_reports;
+        uint8_t supported_reports{};
+
+        std::mutex _response_mutex;
+        std::condition_variable _response_cv;
     private:
         void _init();
 
@@ -115,16 +121,17 @@ namespace logid::backend::hidpp {
         DeviceIndex _index;
 
         std::tuple<uint8_t, uint8_t> _version;
-        uint16_t _pid;
+        uint16_t _pid{};
         std::string _name;
 
-        std::mutex _send_lock;
-        std::mutex _resp_wait_lock;
-        std::condition_variable _resp_cv;
-        std::mutex _slot_lock;
-        std::optional<Report> _report_slot;
+        std::mutex _send_mutex;
 
-        std::mutex _event_handler_lock;
+        typedef std::variant<Report, Report::Hidpp10Error, Report::Hidpp20Error> Response;
+
+        std::optional<Response> _response;
+        std::optional<uint8_t> _sent_sub_id{};
+
+        std::shared_mutex _event_handler_mutex;
         std::list<EventHandler> _event_handlers;
     };
 }
diff --git a/src/logid/backend/hidpp/defs.h b/src/logid/backend/hidpp/defs.h
index 2bde9ae..253f3c0 100644
--- a/src/logid/backend/hidpp/defs.h
+++ b/src/logid/backend/hidpp/defs.h
@@ -19,8 +19,6 @@
 #ifndef LOGID_BACKEND_HIDPP_DEFS_H
 #define LOGID_BACKEND_HIDPP_DEFS_H
 
-#define LOGID_HIDPP_SOFTWARE_ID 2
-
 #include <cstdint>
 
 namespace logid::backend::hidpp {
@@ -42,6 +40,10 @@ namespace logid::backend::hidpp {
         WirelessDevice6 = 6,
     };
 
+    static constexpr uint8_t softwareID = 2;
+    /* For sending reports with no response, use a different SW ID */
+    static constexpr uint8_t noAckSoftwareID = 1;
+
     static constexpr std::size_t ShortParamLength = 3;
     static constexpr std::size_t LongParamLength = 16;
 }
diff --git a/src/logid/backend/hidpp10/Device.cpp b/src/logid/backend/hidpp10/Device.cpp
index bfec9b9..4ec4af9 100644
--- a/src/logid/backend/hidpp10/Device.cpp
+++ b/src/logid/backend/hidpp10/Device.cpp
@@ -25,15 +25,13 @@
 using namespace logid::backend;
 using namespace logid::backend::hidpp10;
 
-Device::Device(const std::string& path,
-               hidpp::DeviceIndex index,
-               std::shared_ptr<raw::DeviceMonitor> monitor, double timeout) :
-        hidpp::Device(path, index, std::move(monitor), timeout) {
+Device::Device(const std::string& path, hidpp::DeviceIndex index,
+               const std::shared_ptr<raw::DeviceMonitor>& monitor, double timeout) :
+        hidpp::Device(path, index, monitor, timeout) {
     assert(version() == std::make_tuple(1, 0));
 }
 
-Device::Device(std::shared_ptr<raw::RawDevice> raw_dev,
-               hidpp::DeviceIndex index,
+Device::Device(std::shared_ptr<raw::RawDevice> raw_dev, hidpp::DeviceIndex index,
                double timeout) : hidpp::Device(std::move(raw_dev), index, timeout) {
     assert(version() == std::make_tuple(1, 0));
 }
@@ -45,44 +43,34 @@ Device::Device(const std::shared_ptr<dj::Receiver>& receiver,
     assert(version() == std::make_tuple(1, 0));
 }
 
-hidpp::Report Device::sendReport(const hidpp::Report& report) {
-    decltype(_responses)::iterator response_slot;
-    while (true) {
-        {
-            std::lock_guard<std::mutex> lock(_response_lock);
-            response_slot = _responses.find(report.subId());
-            if (response_slot == _responses.end()) {
-                response_slot = _responses.emplace(
-                        report.subId(), std::optional<Response>()).first;
-                break;
-            }
-        }
-        std::unique_lock<std::mutex> lock(_response_wait_lock);
-        _response_cv.wait(lock, [this, sub_id = report.subId()]() {
-            std::lock_guard<std::mutex> lock(_response_lock);
-            return _responses.find(sub_id) != _responses.end();
-        });
-    }
+void Device::ResponseSlot::reset() {
+    response.reset();
+    sub_id.reset();
+}
 
-    sendReportNoResponse(report);
-    std::unique_lock<std::mutex> wait(_response_wait_lock);
+hidpp::Report Device::sendReport(const hidpp::Report& report) {
+    auto& response_slot = _responses[report.subId() % SubIDCount];
+
+    std::unique_lock<std::mutex> lock(_response_mutex);
+    _response_cv.wait(lock, [&response_slot]() {
+        return !response_slot.sub_id.has_value();
+    });
+    response_slot.sub_id = report.subId();
+
+    _sendReport(report);
     bool valid = _response_cv.wait_for(
-            wait, io_timeout,
-            [this, &response_slot]() {
-                std::lock_guard<std::mutex> lock(_response_lock);
-                return response_slot->second.has_value();
+            lock, io_timeout,
+            [&response_slot]() {
+                return response_slot.response.has_value();
             });
 
     if (!valid) {
-        std::lock_guard<std::mutex> lock(_response_lock);
-        _responses.erase(response_slot);
+        response_slot.reset();
         throw TimeoutError();
     }
 
-    std::lock_guard<std::mutex> lock(_response_lock);
-    assert(response_slot->second.has_value());
-    auto response = response_slot->second.value();
-    _responses.erase(response_slot);
+    auto response = response_slot.response.value();
+    response_slot.reset();
     if (std::holds_alternative<hidpp::Report>(response))
         return std::get<hidpp::Report>(response);
     else // if(std::holds_alternative<Error::ErrorCode>(response))
@@ -90,7 +78,7 @@ hidpp::Report Device::sendReport(const hidpp::Report& report) {
 }
 
 bool Device::responseReport(const hidpp::Report& report) {
-    std::lock_guard<std::mutex> lock(_response_lock);
+    std::lock_guard<std::mutex> lock(_response_mutex);
     uint8_t sub_id;
 
     bool is_error = false;
@@ -102,15 +90,15 @@ bool Device::responseReport(const hidpp::Report& report) {
         sub_id = report.subId();
     }
 
-    auto response_slot = _responses.find(sub_id);
-    if (response_slot == _responses.end())
+    auto& response_slot = _responses[sub_id % SubIDCount];
+
+    if (!response_slot.sub_id.has_value() || response_slot.sub_id.value() != sub_id)
         return false;
 
     if (is_error) {
-        response_slot->second = static_cast<Error::ErrorCode>(
-                hidpp10_error.error_code);
+        response_slot.response = static_cast<Error::ErrorCode>(hidpp10_error.error_code);
     } else {
-        response_slot->second = report;
+        response_slot.response = report;
     }
 
     _response_cv.notify_all();
diff --git a/src/logid/backend/hidpp10/Device.h b/src/logid/backend/hidpp10/Device.h
index 37b7ed0..9dc8034 100644
--- a/src/logid/backend/hidpp10/Device.h
+++ b/src/logid/backend/hidpp10/Device.h
@@ -24,12 +24,13 @@
 
 #include "../hidpp/Device.h"
 #include "Error.h"
+#include "defs.h"
 
 namespace logid::backend::hidpp10 {
     class Device : public hidpp::Device {
     public:
         Device(const std::string& path, hidpp::DeviceIndex index,
-               std::shared_ptr<raw::DeviceMonitor> monitor, double timeout);
+               const std::shared_ptr<raw::DeviceMonitor>& monitor, double timeout);
 
         Device(std::shared_ptr<raw::RawDevice> raw_dev,
                hidpp::DeviceIndex index, double timeout);
@@ -51,15 +52,16 @@ namespace logid::backend::hidpp10 {
         bool responseReport(const hidpp::Report& report) final;
 
     private:
-        std::mutex _response_lock;
-        std::mutex _response_wait_lock;
-        std::condition_variable _response_cv;
-
         typedef std::variant<hidpp::Report, Error::ErrorCode> Response;
-        std::map<uint8_t, std::optional<Response>> _responses;
+        struct ResponseSlot {
+            std::optional<Response> response;
+            std::optional<uint8_t> sub_id;
+            void reset();
+        };
+        std::array<ResponseSlot, SubIDCount> _responses;
 
-        std::vector<uint8_t> accessRegister(uint8_t sub_id,
-                                            uint8_t address, const std::vector<uint8_t>& params);
+        std::vector<uint8_t> accessRegister(
+                uint8_t sub_id, uint8_t address, const std::vector<uint8_t>& params);
     };
 }
 
diff --git a/src/logid/backend/hidpp10/defs.h b/src/logid/backend/hidpp10/defs.h
index df20622..ff18ed4 100644
--- a/src/logid/backend/hidpp10/defs.h
+++ b/src/logid/backend/hidpp10/defs.h
@@ -24,8 +24,10 @@ namespace logid::backend::hidpp10 {
         SetRegisterShort = 0x80,
         GetRegisterShort = 0x81,
         SetRegisterLong = 0x82,
-        GetRegisterLong = 0x83
+        GetRegisterLong = 0x83,
     };
+
+    static constexpr size_t SubIDCount = 4;
 }
 
 #endif //LOGID_BACKEND_HIDPP10_DEFS_H
\ No newline at end of file
diff --git a/src/logid/backend/hidpp20/Device.cpp b/src/logid/backend/hidpp20/Device.cpp
index 8e650bd..defaabb 100644
--- a/src/logid/backend/hidpp20/Device.cpp
+++ b/src/logid/backend/hidpp20/Device.cpp
@@ -26,9 +26,8 @@ using namespace logid::backend;
 using namespace logid::backend::hidpp20;
 
 Device::Device(const std::string& path, hidpp::DeviceIndex index,
-               std::shared_ptr<raw::DeviceMonitor> monitor, double timeout) :
-        hidpp::Device(path, index,
-                      std::move(monitor), timeout) {
+               const std::shared_ptr<raw::DeviceMonitor>& monitor, double timeout) :
+        hidpp::Device(path, index, monitor, timeout) {
     // TODO: Fix version check
     if (std::get<0>(version()) < 2)
         throw std::runtime_error("Invalid HID++ version");
@@ -68,7 +67,7 @@ std::vector<uint8_t> Device::callFunction(uint8_t feature_index,
         throw hidpp::Report::InvalidReportID();
 
     hidpp::Report request(type, deviceIndex(), feature_index, function,
-                          LOGID_HIDPP_SOFTWARE_ID);
+                          hidpp::softwareID);
     std::copy(params.begin(), params.end(), request.paramBegin());
 
     auto response = this->sendReport(request);
@@ -87,101 +86,85 @@ void Device::callFunctionNoResponse(uint8_t feature_index, uint8_t function,
     else
         throw hidpp::Report::InvalidReportID();
 
-    hidpp::Report request(type, deviceIndex(), feature_index, function,
-                          LOGID_HIDPP_SOFTWARE_ID);
+    hidpp::Report request(type, deviceIndex(), feature_index, function, hidpp::softwareID);
     std::copy(params.begin(), params.end(), request.paramBegin());
 
-    this->sendReportNoResponse(request);
+    this->sendReportNoACK(request);
 }
 
 hidpp::Report Device::sendReport(const hidpp::Report& report) {
-    decltype(_responses)::iterator response_slot;
+    auto& response_slot = _responses[report.feature() % _responses.size()];
 
-    while (true) {
-        {
-            std::lock_guard lock(_response_lock);
-            if (_responses.empty()) {
-                response_slot = _responses.emplace(
-                        2, std::optional<Response>()).first;
-                break;
-            } else if (_responses.size() < response_slots) {
-                uint8_t i = 0;
-                for (auto& x: _responses) {
-                    if (x.first != i + 1) {
-                        ++i;
-                        break;
-                    }
-                    i = x.first;
-                }
-                assert(_responses.count(i) == 0);
+    std::unique_lock<std::mutex> response_lock(_response_mutex);
+    _response_cv.wait(response_lock, [&response_slot]() {
+        return !response_slot.feature.has_value();
+    });
 
-                response_slot = _responses.emplace(
-                        i, std::optional<Response>()).first;
-                break;
-            }
-        }
+    response_slot.feature = report.feature();
 
-        std::unique_lock<std::mutex> lock(_response_wait_lock);
-        _response_cv.wait(lock, [this, sub_id = report.subId()]() {
-            std::lock_guard<std::mutex> lock(_response_lock);
-            return _responses.size() < response_slots;
-        });
-    }
+    _sendReport(report);
 
-    {
-        std::lock_guard<std::mutex> lock(_response_lock);
-        hidpp::Report mod_report{report};
-        mod_report.setSwId(response_slot->first);
-        sendReportNoResponse(std::move(mod_report));
-    }
-
-    std::unique_lock<std::mutex> wait(_response_wait_lock);
-    bool valid = _response_cv.wait_for(wait, io_timeout,
-                                       [this, &response_slot]() {
-                                           std::lock_guard<std::mutex> lock(_response_lock);
-                                           return response_slot->second.has_value();
-                                       });
+    bool valid = _response_cv.wait_for(
+            response_lock, io_timeout,
+            [&response_slot]() {
+                return response_slot.response.has_value();
+            });
 
     if (!valid) {
-        std::lock_guard<std::mutex> lock(_response_lock);
-        _responses.erase(response_slot);
+        response_slot.reset();
         throw TimeoutError();
     }
 
-    std::lock_guard<std::mutex> lock(_response_lock);
-    assert(response_slot->second.has_value());
-    auto response = response_slot->second.value();
-    _responses.erase(response_slot);
+    assert(response_slot.response.has_value());
+    auto response = response_slot.response.value();
+    response_slot.reset();
+
     if (std::holds_alternative<hidpp::Report>(response))
         return std::get<hidpp::Report>(response);
     else // if(std::holds_alternative<Error::ErrorCode>(response))
         throw Error(std::get<Error::ErrorCode>(response));
 }
 
+void Device::sendReportNoACK(const hidpp::Report& report) {
+    hidpp::Report no_ack_report(report);
+    no_ack_report.setSwId(hidpp::noAckSoftwareID);
+    _sendReport(std::move(no_ack_report));
+}
+
 bool Device::responseReport(const hidpp::Report& report) {
-    std::lock_guard<std::mutex> lock(_response_lock);
-    uint8_t sw_id;
+    auto& response_slot = _responses[report.feature() % _responses.size()];
+    std::lock_guard<std::mutex> lock(_response_mutex);
+    uint8_t sw_id, feature;
 
     bool is_error = false;
     hidpp::Report::Hidpp20Error hidpp20_error{};
     if (report.isError20(&hidpp20_error)) {
         is_error = true;
         sw_id = hidpp20_error.software_id;
+        feature = hidpp20_error.feature_index;
     } else {
         sw_id = report.swId();
+        feature = report.feature();
     }
 
-    auto response_slot = _responses.find(sw_id);
-    if (response_slot == _responses.end())
+    if (sw_id != hidpp::softwareID)
         return false;
 
+    if (!response_slot.feature || response_slot.feature.value() != feature) {
+        return false;
+    }
+
     if (is_error) {
-        response_slot->second = static_cast<Error::ErrorCode>(
-                hidpp20_error.error_code);
+        response_slot.response = static_cast<Error::ErrorCode>(hidpp20_error.error_code);
     } else {
-        response_slot->second = report;
+        response_slot.response = report;
     }
 
     _response_cv.notify_all();
     return true;
 }
+
+void Device::ResponseSlot::reset() {
+    response.reset();
+    feature.reset();
+}
diff --git a/src/logid/backend/hidpp20/Device.h b/src/logid/backend/hidpp20/Device.h
index 7fe32bf..4a0e3ae 100644
--- a/src/logid/backend/hidpp20/Device.h
+++ b/src/logid/backend/hidpp20/Device.h
@@ -30,7 +30,7 @@ namespace logid::backend::hidpp20 {
     class Device : public hidpp::Device {
     public:
         Device(const std::string& path, hidpp::DeviceIndex index,
-               std::shared_ptr<raw::DeviceMonitor> monitor, double timeout);
+               const std::shared_ptr<raw::DeviceMonitor>& monitor, double timeout);
 
         Device(std::shared_ptr<raw::RawDevice> raw_device,
                hidpp::DeviceIndex index, double timeout);
@@ -51,17 +51,21 @@ namespace logid::backend::hidpp20 {
 
         hidpp::Report sendReport(const hidpp::Report& report) final;
 
+        void sendReportNoACK(const hidpp::Report& report) final;
+
     protected:
         bool responseReport(const hidpp::Report& report) final;
 
     private:
-        std::mutex _response_lock;
-        std::mutex _response_wait_lock;
-        std::condition_variable _response_cv;
-
-        static constexpr int response_slots = 14;
         typedef std::variant<hidpp::Report, Error::ErrorCode> Response;
-        std::map<uint8_t, std::optional<Response>> _responses;
+        struct ResponseSlot {
+            std::optional<Response> response;
+            std::optional<uint8_t> feature;
+            void reset();
+        };
+
+        /* Multiplex responses on lower nibble of SubID, ignore upper nibble for space */
+        std::array<ResponseSlot, 16> _responses;
     };
 }
 
diff --git a/src/logid/backend/hidpp20/EssentialFeature.cpp b/src/logid/backend/hidpp20/EssentialFeature.cpp
index a52975d..3eadfcb 100644
--- a/src/logid/backend/hidpp20/EssentialFeature.cpp
+++ b/src/logid/backend/hidpp20/EssentialFeature.cpp
@@ -36,8 +36,7 @@ std::vector<uint8_t> EssentialFeature::callFunction(uint8_t function_id,
     else
         throw hidpp::Report::InvalidReportID();
 
-    hidpp::Report request(type, _device->deviceIndex(), _index, function_id,
-                          LOGID_HIDPP_SOFTWARE_ID);
+    hidpp::Report request(type, _device->deviceIndex(), _index, function_id, hidpp::softwareID);
     std::copy(params.begin(), params.end(), request.paramBegin());
 
     auto response = _device->sendReport(request);
diff --git a/src/logid/backend/raw/IOMonitor.cpp b/src/logid/backend/raw/IOMonitor.cpp
index e89fa00..11bce03 100644
--- a/src/logid/backend/raw/IOMonitor.cpp
+++ b/src/logid/backend/raw/IOMonitor.cpp
@@ -86,8 +86,8 @@ void IOMonitor::_listen() {
     _is_running = true;
 
     while (_is_running) {
-        {
-            std::unique_lock<std::mutex> lock(_interrupt_lock);
+        if (_interrupting) {
+            std::unique_lock<std::mutex> lock(_interrupt_mutex);
             _interrupt_cv.wait(lock, [this]() {
                 return !(bool) _interrupting;
             });
diff --git a/src/logid/backend/raw/IOMonitor.h b/src/logid/backend/raw/IOMonitor.h
index 9453dc9..d26f955 100644
--- a/src/logid/backend/raw/IOMonitor.h
+++ b/src/logid/backend/raw/IOMonitor.h
@@ -64,7 +64,7 @@ namespace logid::backend::raw {
         std::atomic_bool _is_running;
 
         std::atomic_bool _interrupting;
-        std::mutex _interrupt_lock;
+        std::mutex _interrupt_mutex;
         std::condition_variable _interrupt_cv;
 
         const int _epoll_fd;
diff --git a/src/logid/backend/raw/RawDevice.cpp b/src/logid/backend/raw/RawDevice.cpp
index 9535535..9f5497c 100644
--- a/src/logid/backend/raw/RawDevice.cpp
+++ b/src/logid/backend/raw/RawDevice.cpp
@@ -155,13 +155,13 @@ void RawDevice::sendReport(const std::vector<uint8_t>& report) {
 }
 
 RawDevice::EvHandlerId RawDevice::addEventHandler(RawEventHandler handler) {
-    std::lock_guard<std::mutex> lock(_event_handler_lock);
+    std::unique_lock<std::shared_mutex> lock(_event_handler_mutex);
     _event_handlers.emplace_front(std::move(handler));
     return _event_handlers.cbegin();
 }
 
 void RawDevice::removeEventHandler(RawDevice::EvHandlerId id) {
-    std::lock_guard<std::mutex> lock(_event_handler_lock);
+    std::unique_lock<std::shared_mutex> lock(_event_handler_mutex);
     _event_handlers.erase(id);
 }
 
@@ -185,7 +185,7 @@ void RawDevice::_readReports() {
 }
 
 void RawDevice::_handleEvent(const std::vector<uint8_t>& report) {
-    std::unique_lock<std::mutex> lock(_event_handler_lock);
+    std::shared_lock<std::shared_mutex> lock(_event_handler_mutex);
     for (auto& handler: _event_handlers)
         if (handler.condition(report))
             handler.callback(report);
diff --git a/src/logid/backend/raw/RawDevice.h b/src/logid/backend/raw/RawDevice.h
index 030c304..ee4e2c9 100644
--- a/src/logid/backend/raw/RawDevice.h
+++ b/src/logid/backend/raw/RawDevice.h
@@ -21,8 +21,7 @@
 
 #include <string>
 #include <vector>
-#include <mutex>
-#include <map>
+#include <shared_mutex>
 #include <atomic>
 #include <future>
 #include <set>
@@ -85,7 +84,7 @@ namespace logid::backend::raw {
         std::shared_ptr<IOMonitor> _io_monitor;
 
         std::list<RawEventHandler> _event_handlers;
-        std::mutex _event_handler_lock;
+        std::shared_mutex _event_handler_mutex;
 
         void _handleEvent(const std::vector<uint8_t>& report);
     };