diff --git a/Source/Core/DolphinQt/Config/Mapping/MappingNumeric.cpp b/Source/Core/DolphinQt/Config/Mapping/MappingNumeric.cpp
index 0d6570e87d..6079bd4881 100644
--- a/Source/Core/DolphinQt/Config/Mapping/MappingNumeric.cpp
+++ b/Source/Core/DolphinQt/Config/Mapping/MappingNumeric.cpp
@@ -83,6 +83,8 @@ MappingBool::MappingBool(MappingWidget* parent, ControllerEmu::NumericSetting<bo
 
   connect(parent, &MappingWidget::ConfigChanged, this, &MappingBool::ConfigChanged);
   connect(parent, &MappingWidget::Update, this, &MappingBool::Update);
+
+  setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Ignored);
 }
 
 void MappingBool::ConfigChanged()
diff --git a/Source/Core/DolphinQt/Config/Mapping/MappingWidget.cpp b/Source/Core/DolphinQt/Config/Mapping/MappingWidget.cpp
index 5ba6e70e29..eb39bac64f 100644
--- a/Source/Core/DolphinQt/Config/Mapping/MappingWidget.cpp
+++ b/Source/Core/DolphinQt/Config/Mapping/MappingWidget.cpp
@@ -9,7 +9,6 @@
 #include <QGroupBox>
 #include <QLabel>
 #include <QPushButton>
-#include <QTimer>
 
 #include "DolphinQt/Config/Mapping/IOWindow.h"
 #include "DolphinQt/Config/Mapping/MappingButton.h"
@@ -29,14 +28,6 @@ MappingWidget::MappingWidget(MappingWindow* parent) : m_parent(parent)
   connect(parent, &MappingWindow::Update, this, &MappingWidget::Update);
   connect(parent, &MappingWindow::Save, this, &MappingWidget::SaveSettings);
   connect(parent, &MappingWindow::ConfigChanged, this, &MappingWidget::ConfigChanged);
-
-  const auto timer = new QTimer(this);
-  connect(timer, &QTimer::timeout, this, [this] {
-    const auto lock = m_parent->GetController()->GetStateLock();
-    emit Update();
-  });
-
-  timer->start(1000 / INDICATOR_UPDATE_FREQ);
 }
 
 MappingWindow* MappingWidget::GetParent() const
@@ -139,31 +130,18 @@ QGroupBox* MappingWidget::CreateGroupBox(const QString& name, ControllerEmu::Con
       setting_widget =
           new MappingBool(this, static_cast<ControllerEmu::NumericSetting<bool>*>(setting.get()));
       break;
+
+    default:
+      // FYI: Widgets for additional types can be implemented as needed.
+      break;
     }
 
     if (setting_widget)
     {
       const auto hbox = new QHBoxLayout;
+
       hbox->addWidget(setting_widget);
-
-      const auto advanced_button = new QPushButton(tr("..."));
-      advanced_button->setFixedWidth(
-          QFontMetrics(font()).boundingRect(advanced_button->text()).width() * 2);
-
-      hbox->addWidget(advanced_button);
-
-      advanced_button->connect(
-          advanced_button, &QPushButton::clicked, [this, &setting = *setting.get()]() {
-            setting.SetExpressionFromValue();
-
-            IOWindow io(this, GetController(), &setting.GetInputReference(), IOWindow::Type::Input);
-            io.exec();
-
-            setting.SimplifyIfPossible();
-
-            ConfigChanged();
-            SaveSettings();
-          });
+      hbox->addWidget(CreateSettingAdvancedMappingButton(*setting));
 
       form_layout->addRow(tr(setting->GetUIName()), hbox);
     }
@@ -198,3 +176,25 @@ ControllerEmu::EmulatedController* MappingWidget::GetController() const
 {
   return m_parent->GetController();
 }
+
+QPushButton*
+MappingWidget::CreateSettingAdvancedMappingButton(ControllerEmu::NumericSettingBase& setting)
+{
+  const auto button = new QPushButton(tr("..."));
+  button->setFixedWidth(QFontMetrics(font()).boundingRect(button->text()).width() * 2);
+
+  button->connect(button, &QPushButton::clicked, [this, &setting]() {
+    if (setting.IsSimpleValue())
+      setting.SetExpressionFromValue();
+
+    IOWindow io(this, GetController(), &setting.GetInputReference(), IOWindow::Type::Input);
+    io.exec();
+
+    setting.SimplifyIfPossible();
+
+    ConfigChanged();
+    SaveSettings();
+  });
+
+  return button;
+}
diff --git a/Source/Core/DolphinQt/Config/Mapping/MappingWidget.h b/Source/Core/DolphinQt/Config/Mapping/MappingWidget.h
index 707332ccd8..851d2c12ce 100644
--- a/Source/Core/DolphinQt/Config/Mapping/MappingWidget.h
+++ b/Source/Core/DolphinQt/Config/Mapping/MappingWidget.h
@@ -17,6 +17,7 @@ class InputConfig;
 class MappingButton;
 class MappingNumeric;
 class MappingWindow;
+class QPushButton;
 class QGroupBox;
 
 namespace ControllerEmu
@@ -24,13 +25,9 @@ namespace ControllerEmu
 class Control;
 class ControlGroup;
 class EmulatedController;
+class NumericSettingBase;
 }  // namespace ControllerEmu
 
-namespace ciface::Core
-{
-class Device;
-}  // namespace ciface::Core
-
 constexpr int INDICATOR_UPDATE_FREQ = 30;
 
 class MappingWidget : public QWidget
@@ -56,6 +53,7 @@ protected:
 
   QGroupBox* CreateGroupBox(ControllerEmu::ControlGroup* group);
   QGroupBox* CreateGroupBox(const QString& name, ControllerEmu::ControlGroup* group);
+  QPushButton* CreateSettingAdvancedMappingButton(ControllerEmu::NumericSettingBase& setting);
 
 private:
   MappingWindow* m_parent;
diff --git a/Source/Core/DolphinQt/Config/Mapping/MappingWindow.cpp b/Source/Core/DolphinQt/Config/Mapping/MappingWindow.cpp
index 2b38fea2aa..dd5768e3f2 100644
--- a/Source/Core/DolphinQt/Config/Mapping/MappingWindow.cpp
+++ b/Source/Core/DolphinQt/Config/Mapping/MappingWindow.cpp
@@ -11,6 +11,7 @@
 #include <QHBoxLayout>
 #include <QPushButton>
 #include <QTabWidget>
+#include <QTimer>
 #include <QVBoxLayout>
 
 #include "Core/Core.h"
@@ -62,6 +63,15 @@ MappingWindow::MappingWindow(QWidget* parent, Type type, int port_num)
   ConnectWidgets();
   SetMappingType(type);
 
+  const auto timer = new QTimer(this);
+  connect(timer, &QTimer::timeout, this, [this] {
+    const auto lock = GetController()->GetStateLock();
+    emit Update();
+  });
+
+  timer->start(1000 / INDICATOR_UPDATE_FREQ);
+
+  GetController()->GetStateLock();
   emit ConfigChanged();
 }
 
@@ -235,6 +245,7 @@ void MappingWindow::OnLoadProfilePressed()
   m_controller->LoadConfig(ini.GetOrCreateSection("Profile"));
   m_controller->UpdateReferences(g_controller_interface);
 
+  GetController()->GetStateLock();
   emit ConfigChanged();
 }
 
@@ -426,6 +437,8 @@ void MappingWindow::OnDefaultFieldsPressed()
 {
   m_controller->LoadDefaults(g_controller_interface);
   m_controller->UpdateReferences(g_controller_interface);
+
+  GetController()->GetStateLock();
   emit ConfigChanged();
   emit Save();
 }
@@ -441,6 +454,8 @@ void MappingWindow::OnClearFieldsPressed()
   m_controller->SetDefaultDevice(default_device);
 
   m_controller->UpdateReferences(g_controller_interface);
+
+  GetController()->GetStateLock();
   emit ConfigChanged();
   emit Save();
 }
diff --git a/Source/Core/DolphinQt/Config/Mapping/WiimoteEmuGeneral.cpp b/Source/Core/DolphinQt/Config/Mapping/WiimoteEmuGeneral.cpp
index 633245a324..0084bc5bee 100644
--- a/Source/Core/DolphinQt/Config/Mapping/WiimoteEmuGeneral.cpp
+++ b/Source/Core/DolphinQt/Config/Mapping/WiimoteEmuGeneral.cpp
@@ -8,6 +8,8 @@
 #include <QFormLayout>
 #include <QGridLayout>
 #include <QGroupBox>
+#include <QLabel>
+#include <QPushButton>
 
 #include "Core/HW/Wiimote.h"
 #include "Core/HW/WiimoteEmu/WiimoteEmu.h"
@@ -22,7 +24,7 @@ WiimoteEmuGeneral::WiimoteEmuGeneral(MappingWindow* window, WiimoteEmuExtension*
     : MappingWidget(window), m_extension_widget(extension)
 {
   CreateMainLayout();
-  Connect(window);
+  Connect();
 }
 
 void WiimoteEmuGeneral::CreateMainLayout()
@@ -45,14 +47,20 @@ void WiimoteEmuGeneral::CreateMainLayout()
       Wiimote::GetWiimoteGroup(GetPort(), WiimoteEmu::WiimoteGroup::Attachments);
   auto* extension = CreateGroupBox(tr("Extension"), extension_group);
   auto* ce_extension = static_cast<ControllerEmu::Attachments*>(extension_group);
-  m_extension_combo = new QComboBox();
+
+  const auto combo_hbox = new QHBoxLayout;
+  combo_hbox->addWidget(m_extension_combo = new QComboBox());
+  combo_hbox->addWidget(m_extension_combo_dynamic_indicator = new QLabel(QString::fromUtf8("🎮")));
+  combo_hbox->addWidget(CreateSettingAdvancedMappingButton(ce_extension->GetSelectionSetting()));
+
+  m_extension_combo_dynamic_indicator->setSizePolicy(QSizePolicy::Maximum, QSizePolicy::Ignored);
 
   for (const auto& attachment : ce_extension->GetAttachmentList())
     m_extension_combo->addItem(tr(attachment->GetDisplayName().c_str()));
 
   extension->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
 
-  static_cast<QFormLayout*>(extension->layout())->insertRow(0, m_extension_combo);
+  static_cast<QFormLayout*>(extension->layout())->insertRow(0, combo_hbox);
 
   layout->addWidget(extension, 0, 3);
   layout->addWidget(CreateGroupBox(tr("Rumble"), Wiimote::GetWiimoteGroup(
@@ -67,11 +75,14 @@ void WiimoteEmuGeneral::CreateMainLayout()
   setLayout(layout);
 }
 
-void WiimoteEmuGeneral::Connect(MappingWindow* window)
+void WiimoteEmuGeneral::Connect()
 {
-  connect(m_extension_combo, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged),
-          this, &WiimoteEmuGeneral::OnAttachmentChanged);
-  connect(window, &MappingWindow::ConfigChanged, this, &WiimoteEmuGeneral::ConfigChanged);
+  connect(m_extension_combo, QOverload<int>::of(&QComboBox::currentIndexChanged), this,
+          &WiimoteEmuGeneral::OnAttachmentChanged);
+  connect(m_extension_combo, QOverload<int>::of(&QComboBox::activated), this,
+          &WiimoteEmuGeneral::OnAttachmentSelected);
+  connect(this, &MappingWidget::ConfigChanged, this, &WiimoteEmuGeneral::ConfigChanged);
+  connect(this, &MappingWidget::Update, this, &WiimoteEmuGeneral::Update);
 }
 
 void WiimoteEmuGeneral::OnAttachmentChanged(int extension)
@@ -79,15 +90,31 @@ void WiimoteEmuGeneral::OnAttachmentChanged(int extension)
   GetParent()->ShowExtensionMotionTabs(extension == WiimoteEmu::ExtensionNumber::NUNCHUK);
 
   m_extension_widget->ChangeExtensionType(extension);
+}
 
+void WiimoteEmuGeneral::OnAttachmentSelected(int extension)
+{
   auto* ce_extension = static_cast<ControllerEmu::Attachments*>(
       Wiimote::GetWiimoteGroup(GetPort(), WiimoteEmu::WiimoteGroup::Attachments));
+
   ce_extension->SetSelectedAttachment(extension);
 
+  ConfigChanged();
   SaveSettings();
 }
 
 void WiimoteEmuGeneral::ConfigChanged()
+{
+  auto* ce_extension = static_cast<ControllerEmu::Attachments*>(
+      Wiimote::GetWiimoteGroup(GetPort(), WiimoteEmu::WiimoteGroup::Attachments));
+
+  m_extension_combo->setCurrentIndex(ce_extension->GetSelectedAttachment());
+
+  m_extension_combo_dynamic_indicator->setVisible(
+      !ce_extension->GetSelectionSetting().IsSimpleValue());
+}
+
+void WiimoteEmuGeneral::Update()
 {
   auto* ce_extension = static_cast<ControllerEmu::Attachments*>(
       Wiimote::GetWiimoteGroup(GetPort(), WiimoteEmu::WiimoteGroup::Attachments));
diff --git a/Source/Core/DolphinQt/Config/Mapping/WiimoteEmuGeneral.h b/Source/Core/DolphinQt/Config/Mapping/WiimoteEmuGeneral.h
index d692f9d9dd..01a11fa8da 100644
--- a/Source/Core/DolphinQt/Config/Mapping/WiimoteEmuGeneral.h
+++ b/Source/Core/DolphinQt/Config/Mapping/WiimoteEmuGeneral.h
@@ -7,6 +7,7 @@
 #include "DolphinQt/Config/Mapping/MappingWidget.h"
 
 class QComboBox;
+class QLabel;
 class WiimoteEmuExtension;
 
 class WiimoteEmuGeneral final : public MappingWidget
@@ -21,12 +22,19 @@ private:
   void LoadSettings() override;
   void SaveSettings() override;
   void CreateMainLayout();
-  void Connect(MappingWindow* window);
+  void Connect();
+
+  // Index changed by code/expression.
   void OnAttachmentChanged(int index);
+  // Selection chosen by user.
+  void OnAttachmentSelected(int index);
+
   void ConfigChanged();
+  void Update();
 
   // Extensions
   QComboBox* m_extension_combo;
+  QLabel* m_extension_combo_dynamic_indicator;
 
   WiimoteEmuExtension* m_extension_widget;
 };
diff --git a/Source/Core/InputCommon/ControllerEmu/ControlGroup/Attachments.cpp b/Source/Core/InputCommon/ControllerEmu/ControlGroup/Attachments.cpp
index e104918fe2..6f980d8c60 100644
--- a/Source/Core/InputCommon/ControllerEmu/ControlGroup/Attachments.cpp
+++ b/Source/Core/InputCommon/ControllerEmu/ControlGroup/Attachments.cpp
@@ -17,12 +17,22 @@ void Attachments::AddAttachment(std::unique_ptr<EmulatedController> att)
 
 u32 Attachments::GetSelectedAttachment() const
 {
-  return m_selected_attachment;
+  const u32 value = m_selection_value.GetValue();
+
+  if (value < m_attachments.size())
+    return value;
+
+  return 0;
 }
 
 void Attachments::SetSelectedAttachment(u32 val)
 {
-  m_selected_attachment = val;
+  m_selection_setting.SetValue(val);
+}
+
+NumericSetting<int>& Attachments::GetSelectionSetting()
+{
+  return m_selection_setting;
 }
 
 const std::vector<std::unique_ptr<EmulatedController>>& Attachments::GetAttachmentList() const
diff --git a/Source/Core/InputCommon/ControllerEmu/ControlGroup/Attachments.h b/Source/Core/InputCommon/ControllerEmu/ControlGroup/Attachments.h
index 81e76eccfe..f92bd8b1fd 100644
--- a/Source/Core/InputCommon/ControllerEmu/ControlGroup/Attachments.h
+++ b/Source/Core/InputCommon/ControllerEmu/ControlGroup/Attachments.h
@@ -12,6 +12,7 @@
 #include "Common/CommonTypes.h"
 #include "InputCommon/ControllerEmu/ControlGroup/ControlGroup.h"
 #include "InputCommon/ControllerEmu/ControllerEmu.h"
+#include "InputCommon/ControllerEmu/Setting/NumericSetting.h"
 
 namespace ControllerEmu
 {
@@ -27,11 +28,14 @@ public:
   u32 GetSelectedAttachment() const;
   void SetSelectedAttachment(u32 val);
 
+  NumericSetting<int>& GetSelectionSetting();
+
   const std::vector<std::unique_ptr<EmulatedController>>& GetAttachmentList() const;
 
 private:
-  std::vector<std::unique_ptr<EmulatedController>> m_attachments;
+  SettingValue<int> m_selection_value;
+  NumericSetting<int> m_selection_setting = {&m_selection_value, {""}, 0, 0, 0};
 
-  std::atomic<u32> m_selected_attachment = {};
+  std::vector<std::unique_ptr<EmulatedController>> m_attachments;
 };
 }  // namespace ControllerEmu
diff --git a/Source/Core/InputCommon/ControllerEmu/ControlGroup/ControlGroup.cpp b/Source/Core/InputCommon/ControllerEmu/ControlGroup/ControlGroup.cpp
index 40ccae24f7..1a262a8dfd 100644
--- a/Source/Core/InputCommon/ControllerEmu/ControlGroup/ControlGroup.cpp
+++ b/Source/Core/InputCommon/ControllerEmu/ControlGroup/ControlGroup.cpp
@@ -74,15 +74,19 @@ void ControlGroup::LoadConfig(IniFile::Section* sec, const std::string& defdev,
 
     ext->SetSelectedAttachment(0);
     u32 n = 0;
-    std::string extname;
-    sec->Get(base + name, &extname, "");
+    std::string attachment_text;
+    sec->Get(base + name, &attachment_text, "");
+
+    // First assume attachment string is a valid expression.
+    // If it instead matches one of the names of our attachments it is overridden below.
+    ext->GetSelectionSetting().GetInputReference().SetExpression(attachment_text);
 
     for (auto& ai : ext->GetAttachmentList())
     {
       ai->SetDefaultDevice(defdev);
       ai->LoadConfig(sec, base + ai->GetName() + "/");
 
-      if (ai->GetName() == extname)
+      if (ai->GetName() == attachment_text)
         ext->SetSelectedAttachment(n);
 
       n++;
@@ -114,8 +118,16 @@ void ControlGroup::SaveConfig(IniFile::Section* sec, const std::string& defdev,
   if (type == GroupType::Attachments)
   {
     auto* const ext = static_cast<Attachments*>(this);
-    sec->Set(base + name, ext->GetAttachmentList()[ext->GetSelectedAttachment()]->GetName(),
-             "None");
+
+    if (ext->GetSelectionSetting().IsSimpleValue())
+    {
+      sec->Set(base + name, ext->GetAttachmentList()[ext->GetSelectedAttachment()]->GetName(),
+               "None");
+    }
+    else
+    {
+      sec->Set(base + name, ext->GetSelectionSetting().GetInputReference().GetExpression(), "None");
+    }
 
     for (auto& ai : ext->GetAttachmentList())
       ai->SaveConfig(sec, base + ai->GetName() + "/");
diff --git a/Source/Core/InputCommon/ControllerEmu/ControllerEmu.cpp b/Source/Core/InputCommon/ControllerEmu/ControllerEmu.cpp
index 5d4d16fe76..a9c5844b48 100644
--- a/Source/Core/InputCommon/ControllerEmu/ControllerEmu.cpp
+++ b/Source/Core/InputCommon/ControllerEmu/ControllerEmu.cpp
@@ -61,7 +61,11 @@ void EmulatedController::UpdateReferences(ciface::ExpressionParser::ControlEnvir
     // Attachments:
     if (ctrlGroup->type == GroupType::Attachments)
     {
-      for (auto& attachment : static_cast<Attachments*>(ctrlGroup.get())->GetAttachmentList())
+      auto* const attachments = static_cast<Attachments*>(ctrlGroup.get());
+
+      attachments->GetSelectionSetting().GetInputReference().UpdateReference(env);
+
+      for (auto& attachment : attachments->GetAttachmentList())
         attachment->UpdateReferences(env);
     }
   }
diff --git a/Source/Core/InputCommon/ControllerEmu/Setting/NumericSetting.cpp b/Source/Core/InputCommon/ControllerEmu/Setting/NumericSetting.cpp
index 3459040824..ab45b64595 100644
--- a/Source/Core/InputCommon/ControllerEmu/Setting/NumericSetting.cpp
+++ b/Source/Core/InputCommon/ControllerEmu/Setting/NumericSetting.cpp
@@ -4,6 +4,8 @@
 
 #include "InputCommon/ControllerEmu/Setting/NumericSetting.h"
 
+#include <sstream>
+
 namespace ControllerEmu
 {
 NumericSettingBase::NumericSettingBase(const NumericSettingDetails& details) : m_details(details)
@@ -25,6 +27,36 @@ const char* NumericSettingBase::GetUIDescription() const
   return m_details.ui_description;
 }
 
+template <>
+void NumericSetting<int>::SetExpressionFromValue()
+{
+  m_value.m_input.SetExpression(ValueToString(GetValue()));
+}
+
+template <>
+void NumericSetting<double>::SetExpressionFromValue()
+{
+  // We must use a dot decimal separator for expression parser.
+  std::ostringstream ss;
+  ss.imbue(std::locale::classic());
+  ss << GetValue();
+
+  m_value.m_input.SetExpression(ss.str());
+}
+
+template <>
+void NumericSetting<bool>::SetExpressionFromValue()
+{
+  // Cast bool to prevent "true"/"false" strings.
+  m_value.m_input.SetExpression(ValueToString(int(GetValue())));
+}
+
+template <>
+SettingType NumericSetting<int>::GetType() const
+{
+  return SettingType::Int;
+}
+
 template <>
 SettingType NumericSetting<double>::GetType() const
 {
diff --git a/Source/Core/InputCommon/ControllerEmu/Setting/NumericSetting.h b/Source/Core/InputCommon/ControllerEmu/Setting/NumericSetting.h
index 6884e7756b..c7298391f4 100644
--- a/Source/Core/InputCommon/ControllerEmu/Setting/NumericSetting.h
+++ b/Source/Core/InputCommon/ControllerEmu/Setting/NumericSetting.h
@@ -16,6 +16,7 @@ namespace ControllerEmu
 {
 enum class SettingType
 {
+  Int,
   Double,
   Bool,
 };
@@ -56,6 +57,8 @@ public:
   virtual InputReference& GetInputReference() = 0;
   virtual const InputReference& GetInputReference() const = 0;
 
+  virtual bool IsSimpleValue() const = 0;
+
   // Convert a literal expression e.g. "7.0" to a regular value. (disables expression parsing)
   virtual void SimplifyIfPossible() = 0;
 
@@ -76,13 +79,14 @@ template <typename T>
 class SettingValue;
 
 template <typename T>
-class NumericSetting : public NumericSettingBase
+class NumericSetting final : public NumericSettingBase
 {
 public:
   using ValueType = T;
 
-  static_assert(std::is_same<ValueType, double>() || std::is_same<ValueType, bool>(),
-                "NumericSetting is only implemented for double and bool.");
+  static_assert(std::is_same<ValueType, int>() || std::is_same<ValueType, double>() ||
+                    std::is_same<ValueType, bool>(),
+                "NumericSetting is only implemented for int, double, and bool.");
 
   NumericSetting(SettingValue<ValueType>* value, const NumericSettingDetails& details,
                  ValueType default_value, ValueType min_value, ValueType max_value)
@@ -114,7 +118,7 @@ public:
       section.Set(group_name + m_details.ini_name, m_value.m_input.GetExpression(), "");
   }
 
-  bool IsSimpleValue() const { return m_value.IsSimpleValue(); }
+  bool IsSimpleValue() const override { return m_value.IsSimpleValue(); }
 
   void SimplifyIfPossible() override
   {
@@ -123,15 +127,7 @@ public:
       m_value.SetValue(value);
   }
 
-  void SetExpressionFromValue() override
-  {
-    if (!IsSimpleValue())
-      return;
-
-    // Cast to double to prevent bool -> "true"/"false" strings.
-    m_value.m_input.SetExpression(ValueToString(static_cast<double>(GetValue())));
-  }
-
+  void SetExpressionFromValue() override;
   InputReference& GetInputReference() override { return m_value.m_input; }
   const InputReference& GetInputReference() const override { return m_value.m_input; }