diff --git a/.github/workflows/format.yml b/.github/workflows/format.yml
index 2eab4970..17380db7 100644
--- a/.github/workflows/format.yml
+++ b/.github/workflows/format.yml
@@ -17,6 +17,7 @@ jobs:
           --style=file \
           ISLE/*.cpp ISLE/*.h \
           LEGO1/*.cpp LEGO1/*.h \
+          LEGO1/mxstl/*.h \
           LEGO1/realtime/*.cpp LEGO1/realtime/*.h \
           LEGO1/tgl/*.h \
           LEGO1/tgl/d3drm/*.cpp LEGO1/tgl/d3drm/*.h \
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4a60e3d4..ed3c29cf 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -230,6 +230,8 @@ if (MINGW)
 endif()
 
 # Additional include directories
+
+target_include_directories(lego1 PRIVATE "${CMAKE_SOURCE_DIR}/util")
 target_include_directories(lego1 PUBLIC "${CMAKE_SOURCE_DIR}/3rdparty/vec")
 target_include_directories(lego1 PRIVATE "${CMAKE_SOURCE_DIR}/3rdparty/flic")
 target_include_directories(lego1 PRIVATE "${CMAKE_SOURCE_DIR}/3rdparty/smk")
@@ -264,6 +266,8 @@ if (ISLE_BUILD_APP)
     ISLE/define.cpp
   )
 
+  target_include_directories(isle PRIVATE "${CMAKE_SOURCE_DIR}/util")
+
   # Include LEGO1 headers in ISLE
   target_include_directories(isle PRIVATE "${CMAKE_SOURCE_DIR}/LEGO1")
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 1a698a7d..0c65bc1c 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -27,6 +27,7 @@ This repository currently has only one goal: accuracy to the original executable
 * [`ISLE`](/ISLE): Decompilation of `ISLE.EXE`. It depends on some code in `LEGO1`.
 * [`LEGO1`](/LEGO1): Decompilation of `LEGO1.DLL`. This folder contains code from Mindscape's custom in-house engine called **Omni** (file pattern: `mx*`), the LEGO Island-specific extensions for Omni and the game's code (file pattern: `lego*`) as well as several utility libraries developed by Mindscape.
 * [`tools`](/tools): A set of tools aiding in the decompilation effort.
+* [`util`](/util): Utility headers aiding in the decompilation effort.
 
 ## Tooling
 
diff --git a/ISLE/isleapp.cpp b/ISLE/isleapp.cpp
index 1d4d4641..8d1fe268 100644
--- a/ISLE/isleapp.cpp
+++ b/ISLE/isleapp.cpp
@@ -24,6 +24,10 @@
 
 #include <dsound.h>
 
+// Might be static functions of IsleApp
+BOOL FindExistingInstance(void);
+BOOL StartDirectSound(void);
+
 // FUNCTION: ISLE 0x401000
 IsleApp::IsleApp()
 {
@@ -169,9 +173,6 @@ void IsleApp::SetupVideoFlags(
 	}
 }
 
-BOOL FindExistingInstance(void);
-BOOL StartDirectSound(void);
-
 // FUNCTION: ISLE 0x401610
 int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
 {
@@ -389,52 +390,46 @@ LRESULT WINAPI WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 		}
 		return DefWindowProcA(hWnd, uMsg, wParam, lParam);
 	case WM_DISPLAYCHANGE:
-		if (g_isle && VideoManager() && g_isle->m_fullScreen && VideoManager()->GetDirect3D() &&
-			VideoManager()->GetDirect3D()->GetDeviceModeFinder()) {
-			int targetWidth = LOWORD(lParam);
-			int targetHeight = HIWORD(lParam);
-			int targetDepth = wParam;
+		if (g_isle && VideoManager() && g_isle->m_fullScreen && VideoManager()->GetDirect3D()) {
+			if (VideoManager()->GetDirect3D()->GetDeviceModeFinder()) {
+				int targetDepth = wParam;
+				int targetWidth = LOWORD(lParam);
+				int targetHeight = HIWORD(lParam);
 
-			if (g_waitingForTargetDepth) {
-				g_waitingForTargetDepth = 0;
-				g_targetDepth = targetDepth;
-			}
-			else {
-				BOOL valid = FALSE;
-				if (targetWidth == g_targetWidth && targetHeight == g_targetHeight && g_targetDepth == targetDepth) {
-					valid = TRUE;
+				if (g_waitingForTargetDepth) {
+					g_waitingForTargetDepth = 0;
+					g_targetDepth = targetDepth;
 				}
+				else {
+					BOOL valid = FALSE;
 
-				if (g_rmDisabled) {
-					if (valid) {
-						g_reqEnableRMDevice = 1;
+					if (g_targetWidth == targetWidth && g_targetHeight == targetHeight &&
+						g_targetDepth == targetDepth) {
+						valid = TRUE;
+					}
+
+					if (g_rmDisabled) {
+						if (valid) {
+							g_reqEnableRMDevice = 1;
+						}
+					}
+					else if (!valid) {
+						g_rmDisabled = 1;
+						Lego()->StartTimer();
+						VideoManager()->DisableRMDevice();
 					}
-				}
-				else if (!valid) {
-					g_rmDisabled = 1;
-					Lego()->StartTimer();
-					VideoManager()->DisableRMDevice();
 				}
 			}
 		}
 		return DefWindowProcA(hWnd, uMsg, wParam, lParam);
-	case WM_SETCURSOR:
-		if (g_isle) {
-			HCURSOR hCursor = g_isle->m_cursorCurrent;
-			if (hCursor == g_isle->m_cursorBusy || hCursor == g_isle->m_cursorNo || !hCursor) {
-				SetCursor(hCursor);
-				return 0;
-			}
-		}
-		break;
 	case WM_KEYDOWN:
 		// While this probably should be (HIWORD(lParam) & KF_REPEAT), this seems
 		// to be what the assembly is actually doing
 		if (lParam & (KF_REPEAT << 16)) {
 			return DefWindowProcA(hWnd, uMsg, wParam, lParam);
 		}
-		keyCode = wParam;
 		type = c_notificationKeyPress;
+		keyCode = wParam;
 		break;
 	case WM_MOUSEMOVE:
 		g_mousemoved = 1;
@@ -457,6 +452,13 @@ LRESULT WINAPI WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
 			return 0;
 		}
 		break;
+	case WM_SETCURSOR:
+		if (g_isle && (g_isle->m_cursorCurrent == g_isle->m_cursorBusy ||
+					   g_isle->m_cursorCurrent == g_isle->m_cursorNo || !g_isle->m_cursorCurrent)) {
+			SetCursor(g_isle->m_cursorCurrent);
+			return 0;
+		}
+		break;
 	default:
 		return DefWindowProcA(hWnd, uMsg, wParam, lParam);
 	}
@@ -812,10 +814,8 @@ inline void IsleApp::Tick(BOOL sleepIfNotNextFrame)
 			}
 			this->m_gameStarted = 1;
 		}
-		return;
 	}
-
-	if (sleepIfNotNextFrame != 0)
+	else if (sleepIfNotNextFrame != 0)
 		Sleep(0);
 }
 
diff --git a/LEGO1/mxatomidcounter.h b/LEGO1/mxatomidcounter.h
index c75c2b5c..8fb5ae97 100644
--- a/LEGO1/mxatomidcounter.h
+++ b/LEGO1/mxatomidcounter.h
@@ -1,7 +1,7 @@
 #ifndef MXATOMIDCOUNTER_H
 #define MXATOMIDCOUNTER_H
 
-#include "compat.h" // STL
+#include "mxstl/stlcompat.h"
 #include "mxstring.h"
 
 // Counts the number of existing MxAtomId objects based
diff --git a/LEGO1/mxcompositepresenter.h b/LEGO1/mxcompositepresenter.h
index 7479a8b7..a506505e 100644
--- a/LEGO1/mxcompositepresenter.h
+++ b/LEGO1/mxcompositepresenter.h
@@ -1,9 +1,9 @@
 #ifndef MXCOMPOSITEPRESENTER_H
 #define MXCOMPOSITEPRESENTER_H
 
-#include "compat.h" // STL
 #include "mxactionnotificationparam.h"
 #include "mxpresenter.h"
+#include "mxstl/stlcompat.h"
 
 class MxCompositePresenterList : public list<MxPresenter*> {};
 
diff --git a/LEGO1/mxdiskstreamcontroller.h b/LEGO1/mxdiskstreamcontroller.h
index bed571f4..2de006d1 100644
--- a/LEGO1/mxdiskstreamcontroller.h
+++ b/LEGO1/mxdiskstreamcontroller.h
@@ -1,9 +1,9 @@
 #ifndef MXDISKSTREAMCONTROLLER_H
 #define MXDISKSTREAMCONTROLLER_H
 
-#include "compat.h" // STL
 #include "decomp.h"
 #include "mxdsbuffer.h"
+#include "mxstl/stlcompat.h"
 #include "mxstreamcontroller.h"
 #include "mxtypes.h"
 
diff --git a/LEGO1/mxnotificationmanager.h b/LEGO1/mxnotificationmanager.h
index a26f3748..9ab9c733 100644
--- a/LEGO1/mxnotificationmanager.h
+++ b/LEGO1/mxnotificationmanager.h
@@ -1,10 +1,10 @@
 #ifndef MXNOTIFICATIONMANAGER_H
 #define MXNOTIFICATIONMANAGER_H
 
-#include "compat.h"
 #include "mxcore.h"
 #include "mxcriticalsection.h"
 #include "mxnotificationparam.h"
+#include "mxstl/stlcompat.h"
 #include "mxtypes.h"
 
 class MxNotification {
diff --git a/LEGO1/mxramstreamcontroller.cpp b/LEGO1/mxramstreamcontroller.cpp
index e16e6190..f97486c2 100644
--- a/LEGO1/mxramstreamcontroller.cpp
+++ b/LEGO1/mxramstreamcontroller.cpp
@@ -42,11 +42,19 @@ MxResult MxRAMStreamController::vtable0x20(MxDSAction* p_action)
 	return FAILURE;
 }
 
-// STUB: LEGO1 0x100c6320
-MxResult MxRAMStreamController::vtable0x24(undefined4 p_unknown)
+// FUNCTION: LEGO1 0x100c6320
+MxResult MxRAMStreamController::vtable0x24(MxDSAction* p_action)
 {
-	// TODO STUB
-	return FAILURE;
+	MxDSAction action;
+	do {
+		if (m_action0x60 != NULL) {
+			delete m_action0x60;
+			m_action0x60 = NULL;
+		}
+		action = *p_action;
+		MxStreamController::vtable0x24(&action);
+	} while (m_action0x60 != NULL);
+	return SUCCESS;
 }
 
 // STUB: LEGO1 0x100d0d80
diff --git a/LEGO1/mxramstreamcontroller.h b/LEGO1/mxramstreamcontroller.h
index 26e9a4e1..fad2a80c 100644
--- a/LEGO1/mxramstreamcontroller.h
+++ b/LEGO1/mxramstreamcontroller.h
@@ -26,7 +26,7 @@ class MxRAMStreamController : public MxStreamController {
 
 	virtual MxResult Open(const char* p_filename) override;
 	virtual MxResult vtable0x20(MxDSAction* p_action) override;
-	virtual MxResult vtable0x24(undefined4 p_unknown) override;
+	virtual MxResult vtable0x24(MxDSAction* p_action) override;
 
 private:
 	MxDSBuffer m_buffer;
diff --git a/LEGO1/mxstl.h b/LEGO1/mxstl/mxstl.h
similarity index 100%
rename from LEGO1/mxstl.h
rename to LEGO1/mxstl/mxstl.h
diff --git a/LEGO1/mxstl/stlcompat.h b/LEGO1/mxstl/stlcompat.h
new file mode 100644
index 00000000..bc0076bf
--- /dev/null
+++ b/LEGO1/mxstl/stlcompat.h
@@ -0,0 +1,18 @@
+#ifndef STLCOMPAT_H
+#define STLCOMPAT_H
+
+#include "compat.h"
+
+#if defined(_MSC_VER) && _MSC_VER <= MSVC420_VERSION
+// Disable "nonstandard extension used : 'bool'" warning spam
+#pragma warning(disable : 4237)
+#include "mxstl.h"
+#else
+#include <algorithm>
+#include <list>
+#include <set>
+using std::list;
+using std::set;
+#endif
+
+#endif // STLCOMPAT_H
diff --git a/LEGO1/mxstreamcontroller.cpp b/LEGO1/mxstreamcontroller.cpp
index cdc8eff3..6fafb2c7 100644
--- a/LEGO1/mxstreamcontroller.cpp
+++ b/LEGO1/mxstreamcontroller.cpp
@@ -117,11 +117,20 @@ MxResult MxStreamController::vtable0x20(MxDSAction* p_action)
 	return result;
 }
 
-// STUB: LEGO1 0x100c1740
-MxResult MxStreamController::vtable0x24(undefined4 p_unknown)
+// FUNCTION: LEGO1 0x100c1740
+MxResult MxStreamController::vtable0x24(MxDSAction* p_action)
 {
-	// TODO STUB
-	return FAILURE;
+	MxAutoLocker locker(&m_criticalSection);
+	vtable0x30(p_action);
+	m_action0x60 = m_unkList0x54.Find(p_action, TRUE);
+	if (m_action0x60 == NULL) {
+		return FAILURE;
+	}
+	else {
+		p_action->SetUnknown24(m_action0x60->GetUnknown24());
+		p_action->SetObjectId(m_action0x60->GetObjectId());
+		return FUN_100c1f00(m_action0x60);
+	}
 }
 
 // FUNCTION: LEGO1 0x100c1800
@@ -153,9 +162,25 @@ MxResult MxStreamController::vtable0x2c(MxDSAction* p_action, MxU32 p_bufferval)
 	return FUN_100c1800(p_action, (p_bufferval / m_provider->GetFileSize()) * m_provider->GetFileSize());
 }
 
-// STUB: LEGO1 0x100c1ce0
-MxResult MxStreamController::vtable0x30(undefined4 p_unknown)
+// FUNCTION: LEGO1 0x100c1ce0
+MxResult MxStreamController::vtable0x30(MxDSAction* p_unknown)
 {
+	MxAutoLocker locker(&m_criticalSection);
+	MxResult result = FAILURE;
+	MxDSAction* action = m_unkList0x3c.Find(p_unknown, TRUE);
+	if (action != NULL) {
+		MxNextActionDataStart* data = m_nextActionList.Find(action->GetObjectId(), action->GetUnknown24());
+		delete action;
+		delete data;
+		result = SUCCESS;
+	}
+	return result;
+}
+
+// STUB: LEGO1 0x100c1f00
+MxResult MxStreamController::FUN_100c1f00(MxDSAction* p_action)
+{
+	// TODO
 	return FAILURE;
 }
 
diff --git a/LEGO1/mxstreamcontroller.h b/LEGO1/mxstreamcontroller.h
index 80ff9e35..9a763ba1 100644
--- a/LEGO1/mxstreamcontroller.h
+++ b/LEGO1/mxstreamcontroller.h
@@ -1,13 +1,13 @@
 #ifndef MXSTREAMCONTROLLER_H
 #define MXSTREAMCONTROLLER_H
 
-#include "compat.h" // STL
 #include "decomp.h"
 #include "mxatomid.h"
 #include "mxcore.h"
 #include "mxcriticalsection.h"
 #include "mxdsaction.h"
 #include "mxdsobject.h"
+#include "mxstl/stlcompat.h"
 #include "mxstreamlist.h"
 #include "mxstreamprovider.h"
 
@@ -36,14 +36,15 @@ class MxStreamController : public MxCore {
 	virtual MxResult vtable0x18(undefined4 p_unknown, undefined4 p_unknown2); // vtable+0x18
 	virtual MxResult vtable0x1C(undefined4 p_unknown, undefined4 p_unknown2); // vtable+0x1c
 	virtual MxResult vtable0x20(MxDSAction* p_action);                        // vtable+0x20
-	virtual MxResult vtable0x24(undefined4 p_unknown);                        // vtable+0x24
+	virtual MxResult vtable0x24(MxDSAction* p_unknown);                       // vtable+0x24
 	MxResult FUN_100c1800(MxDSAction* p_action, MxU32 p_val);
 	virtual MxResult vtable0x28();                                        // vtable+0x28
 	virtual MxResult vtable0x2c(MxDSAction* p_action, MxU32 p_bufferval); // vtable+0x2c
-	virtual MxResult vtable0x30(undefined4 p_unknown);                    // vtable+0x30
+	virtual MxResult vtable0x30(MxDSAction* p_unknown);                   // vtable+0x30
 
 	MxBool FUN_100c20d0(MxDSObject& p_obj);
 	MxResult FUN_100c1a00(MxDSAction* p_action, MxU32 p_bufferval);
+	MxResult FUN_100c1f00(MxDSAction* p_action);
 
 	inline MxAtomId& GetAtom() { return atom; };
 
diff --git a/LEGO1/mxstreamlist.h b/LEGO1/mxstreamlist.h
index 46024be5..2a9e7351 100644
--- a/LEGO1/mxstreamlist.h
+++ b/LEGO1/mxstreamlist.h
@@ -1,10 +1,10 @@
 #ifndef MXSTREAMLIST_H
 #define MXSTREAMLIST_H
 
-#include "compat.h" // STL
 #include "mxdsaction.h"
 #include "mxdssubscriber.h"
 #include "mxnextactiondatastart.h"
+#include "mxstl/stlcompat.h"
 
 template <class T>
 class MxStreamList : public list<T> {};
diff --git a/LEGO1/mxticklemanager.h b/LEGO1/mxticklemanager.h
index b7d90763..85994ef5 100644
--- a/LEGO1/mxticklemanager.h
+++ b/LEGO1/mxticklemanager.h
@@ -1,8 +1,8 @@
 #ifndef MXTICKLEMANAGER_H
 #define MXTICKLEMANAGER_H
 
-#include "compat.h"
 #include "mxcore.h"
+#include "mxstl/stlcompat.h"
 #include "mxtypes.h"
 
 class MxTickleClient {
diff --git a/LEGO1/realtime/matrix.cpp b/LEGO1/realtime/matrix.cpp
index 7b2a94b3..3ba63ca5 100644
--- a/LEGO1/realtime/matrix.cpp
+++ b/LEGO1/realtime/matrix.cpp
@@ -1,7 +1,7 @@
 
 #include "matrix.h"
 
-#include "../decomp.h"
+#include "decomp.h"
 #include "math.h"
 
 #include <memory.h>
diff --git a/LEGO1/realtime/orientableroi.cpp b/LEGO1/realtime/orientableroi.cpp
index 651a1ac7..e03b78cb 100644
--- a/LEGO1/realtime/orientableroi.cpp
+++ b/LEGO1/realtime/orientableroi.cpp
@@ -1,6 +1,6 @@
 #include "orientableroi.h"
 
-#include "../decomp.h"
+#include "decomp.h"
 
 DECOMP_SIZE_ASSERT(OrientableROI, 0xdc)
 
diff --git a/LEGO1/realtime/roi.h b/LEGO1/realtime/roi.h
index 66c17a84..40cff140 100644
--- a/LEGO1/realtime/roi.h
+++ b/LEGO1/realtime/roi.h
@@ -3,9 +3,9 @@
 
 // ROI stands for Real-time Object Instance.
 
-#include "../compat.h"
-#include "../mxstl.h"
+#include "../mxstl/stlcompat.h"
 #include "../realtime/realtime.h"
+#include "compat.h"
 #include "lodlist.h"
 #include "vector.h"
 
diff --git a/LEGO1/realtime/vector.cpp b/LEGO1/realtime/vector.cpp
index 1d41470c..54df74e4 100644
--- a/LEGO1/realtime/vector.cpp
+++ b/LEGO1/realtime/vector.cpp
@@ -1,7 +1,7 @@
 
 #include "vector.h"
 
-#include "../decomp.h"
+#include "decomp.h"
 
 #include <math.h>
 #include <memory.h>
diff --git a/LEGO1/tgl/d3drm/impl.h b/LEGO1/tgl/d3drm/impl.h
index bbc7baa0..89894c2d 100644
--- a/LEGO1/tgl/d3drm/impl.h
+++ b/LEGO1/tgl/d3drm/impl.h
@@ -1,6 +1,6 @@
 
-#include "../../decomp.h"
 #include "../tgl.h"
+#include "decomp.h"
 
 #include <d3drm.h>
 
diff --git a/LEGO1/viewmanager/viewlodlist.h b/LEGO1/viewmanager/viewlodlist.h
index 12817ff9..d695624f 100644
--- a/LEGO1/viewmanager/viewlodlist.h
+++ b/LEGO1/viewmanager/viewlodlist.h
@@ -1,9 +1,9 @@
 #ifndef VIEWLODLIST_H
 #define VIEWLODLIST_H
 
-#include "../compat.h"
 #include "../realtime/lodlist.h"
 #include "assert.h"
+#include "compat.h"
 
 #pragma warning(disable : 4786)
 
diff --git a/LEGO1/viewmanager/viewroi.cpp b/LEGO1/viewmanager/viewroi.cpp
index 47cb71e8..47f340ac 100644
--- a/LEGO1/viewmanager/viewroi.cpp
+++ b/LEGO1/viewmanager/viewroi.cpp
@@ -1,6 +1,6 @@
 #include "viewroi.h"
 
-#include "../decomp.h"
+#include "decomp.h"
 
 DECOMP_SIZE_ASSERT(ViewROI, 0xe0)
 
diff --git a/LEGO1/compat.h b/util/compat.h
similarity index 71%
rename from LEGO1/compat.h
rename to util/compat.h
index 9616b254..c1175cd2 100644
--- a/LEGO1/compat.h
+++ b/util/compat.h
@@ -1,5 +1,5 @@
-#ifndef ISLECOMPAT_H
-#define ISLECOMPAT_H
+#ifndef COMPAT_H
+#define COMPAT_H
 
 // Various macros to enable compiling with other/newer compilers.
 
@@ -11,9 +11,6 @@
 #define COMPAT_CONST
 #endif
 
-// DIsable "nonstandard extension used : 'bool'" warning spam
-#pragma warning(disable : 4237)
-
 // Disable "identifier was truncated to '255' characters" warning.
 // Impossible to avoid this if using STL map or set.
 // This removes most (but not all) occurrences of the warning.
@@ -21,17 +18,6 @@
 
 #define MSVC420_VERSION 1020
 
-// STL compatibility.
-#if defined(_MSC_VER) && _MSC_VER <= MSVC420_VERSION
-#include "mxstl.h"
-#else
-#include <algorithm>
-#include <list>
-#include <set>
-using std::list;
-using std::set;
-#endif
-
 // We use `override` so newer compilers can tell us our vtables are valid,
 // however this keyword was added in C++11, so we define it as empty for
 // compatibility with older compilers.
@@ -39,4 +25,4 @@ using std::set;
 #define override
 #endif
 
-#endif // ISLECOMPAT_H
+#endif // COMPAT_H
diff --git a/LEGO1/decomp.h b/util/decomp.h
similarity index 100%
rename from LEGO1/decomp.h
rename to util/decomp.h