diff --git a/core/os/os.cpp b/core/os/os.cpp
index 59a0579ce36..1e9dbd2a184 100644
--- a/core/os/os.cpp
+++ b/core/os/os.cpp
@@ -536,9 +536,14 @@ bool OS::has_feature(const String &p_feature) {
 		return true;
 	}
 
-	if (has_server_feature_callback && has_server_feature_callback(p_feature)) {
-		return true;
+	if (has_server_feature_callback) {
+		return has_server_feature_callback(p_feature);
 	}
+#ifdef DEBUG_ENABLED
+	else if (is_stdout_verbose()) {
+		WARN_PRINT_ONCE("Server features cannot be checked before RenderingServer has been created. If you are checking a server feature, consider moving your OS::has_feature call after INITIALIZATION_LEVEL_SERVERS.");
+	}
+#endif
 
 	if (ProjectSettings::get_singleton()->has_custom_feature(p_feature)) {
 		return true;
diff --git a/core/register_core_types.cpp b/core/register_core_types.cpp
index 3a578d01a6b..685ba9d3d98 100644
--- a/core/register_core_types.cpp
+++ b/core/register_core_types.cpp
@@ -313,17 +313,28 @@ void register_core_settings() {
 	GLOBAL_DEF("threading/worker_pool/low_priority_thread_ratio", 0.3);
 }
 
+void register_early_core_singletons() {
+	GDREGISTER_CLASS(core_bind::Engine);
+	Engine::get_singleton()->add_singleton(Engine::Singleton("Engine", core_bind::Engine::get_singleton()));
+
+	GDREGISTER_CLASS(ProjectSettings);
+	Engine::get_singleton()->add_singleton(Engine::Singleton("ProjectSettings", ProjectSettings::get_singleton()));
+
+	GDREGISTER_CLASS(core_bind::OS);
+	Engine::get_singleton()->add_singleton(Engine::Singleton("OS", core_bind::OS::get_singleton()));
+
+	GDREGISTER_CLASS(Time);
+	Engine::get_singleton()->add_singleton(Engine::Singleton("Time", Time::get_singleton()));
+}
+
 void register_core_singletons() {
 	OS::get_singleton()->benchmark_begin_measure("Core", "Register Singletons");
 
-	GDREGISTER_CLASS(ProjectSettings);
 	GDREGISTER_ABSTRACT_CLASS(IP);
 	GDREGISTER_CLASS(core_bind::Geometry2D);
 	GDREGISTER_CLASS(core_bind::Geometry3D);
 	GDREGISTER_CLASS(core_bind::ResourceLoader);
 	GDREGISTER_CLASS(core_bind::ResourceSaver);
-	GDREGISTER_CLASS(core_bind::OS);
-	GDREGISTER_CLASS(core_bind::Engine);
 	GDREGISTER_CLASS(core_bind::special::ClassDB);
 	GDREGISTER_CLASS(core_bind::Marshalls);
 	GDREGISTER_CLASS(TranslationServer);
@@ -331,23 +342,18 @@ void register_core_singletons() {
 	GDREGISTER_CLASS(InputMap);
 	GDREGISTER_CLASS(Expression);
 	GDREGISTER_CLASS(core_bind::EngineDebugger);
-	GDREGISTER_CLASS(Time);
 
-	Engine::get_singleton()->add_singleton(Engine::Singleton("ProjectSettings", ProjectSettings::get_singleton()));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("IP", IP::get_singleton(), "IP"));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("Geometry2D", core_bind::Geometry2D::get_singleton()));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("Geometry3D", core_bind::Geometry3D::get_singleton()));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("ResourceLoader", core_bind::ResourceLoader::get_singleton()));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("ResourceSaver", core_bind::ResourceSaver::get_singleton()));
-	Engine::get_singleton()->add_singleton(Engine::Singleton("OS", core_bind::OS::get_singleton()));
-	Engine::get_singleton()->add_singleton(Engine::Singleton("Engine", core_bind::Engine::get_singleton()));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("ClassDB", _classdb));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("Marshalls", core_bind::Marshalls::get_singleton()));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("TranslationServer", TranslationServer::get_singleton()));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("Input", Input::get_singleton()));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("InputMap", InputMap::get_singleton()));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("EngineDebugger", core_bind::EngineDebugger::get_singleton()));
-	Engine::get_singleton()->add_singleton(Engine::Singleton("Time", Time::get_singleton()));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("GDExtensionManager", GDExtensionManager::get_singleton()));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("ResourceUID", ResourceUID::get_singleton()));
 	Engine::get_singleton()->add_singleton(Engine::Singleton("WorkerThreadPool", worker_thread_pool));
diff --git a/core/register_core_types.h b/core/register_core_types.h
index eba569272ee..b8db5c5d260 100644
--- a/core/register_core_types.h
+++ b/core/register_core_types.h
@@ -34,6 +34,7 @@
 void register_core_types();
 void register_core_settings();
 void register_core_extensions();
+void register_early_core_singletons();
 void register_core_singletons();
 void unregister_core_types();
 void unregister_core_extensions();
diff --git a/main/main.cpp b/main/main.cpp
index f002e227660..123114ce8d0 100644
--- a/main/main.cpp
+++ b/main/main.cpp
@@ -733,6 +733,7 @@ Error Main::test_setup() {
 	physics_server_2d_manager = memnew(PhysicsServer2DManager);
 
 	// From `Main::setup2()`.
+	register_early_core_singletons();
 	initialize_modules(MODULE_INITIALIZATION_LEVEL_CORE);
 	register_core_extensions();
 
@@ -1869,12 +1870,55 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 	if (editor) {
 		Engine::get_singleton()->set_editor_hint(true);
 		Engine::get_singleton()->set_extension_reloading_enabled(true);
+
+		main_args.push_back("--editor");
+		if (!init_windowed && !init_fullscreen) {
+			init_maximized = true;
+			window_mode = DisplayServer::WINDOW_MODE_MAXIMIZED;
+		}
+	}
+
+	if (!project_manager && !editor) {
+		// If we didn't find a project, we fall back to the project manager.
+		project_manager = !found_project && !cmdline_tool;
+	}
+
+	if (project_manager) {
+		Engine::get_singleton()->set_project_manager_hint(true);
 	}
 #endif
 
+	OS::get_singleton()->set_cmdline(execpath, main_args, user_args);
+
+	Engine::get_singleton()->set_physics_ticks_per_second(GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "physics/common/physics_ticks_per_second", PROPERTY_HINT_RANGE, "1,1000,1"), 60));
+	Engine::get_singleton()->set_max_physics_steps_per_frame(GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "physics/common/max_physics_steps_per_frame", PROPERTY_HINT_RANGE, "1,100,1"), 8));
+	Engine::get_singleton()->set_physics_jitter_fix(GLOBAL_DEF("physics/common/physics_jitter_fix", 0.5));
+	Engine::get_singleton()->set_max_fps(GLOBAL_DEF(PropertyInfo(Variant::INT, "application/run/max_fps", PROPERTY_HINT_RANGE, "0,1000,1"), 0));
+	if (max_fps >= 0) {
+		Engine::get_singleton()->set_max_fps(max_fps);
+	}
+
 	// Initialize user data dir.
 	OS::get_singleton()->ensure_user_data_dir();
 
+	OS::get_singleton()->set_low_processor_usage_mode(GLOBAL_DEF("application/run/low_processor_mode", false));
+	OS::get_singleton()->set_low_processor_usage_mode_sleep_usec(
+			GLOBAL_DEF(PropertyInfo(Variant::INT, "application/run/low_processor_mode_sleep_usec", PROPERTY_HINT_RANGE, "0,33200,1,or_greater"), 6900)); // Roughly 144 FPS
+
+	GLOBAL_DEF("application/run/delta_smoothing", true);
+	if (!delta_smoothing_override) {
+		OS::get_singleton()->set_delta_smoothing(GLOBAL_GET("application/run/delta_smoothing"));
+	}
+
+	GLOBAL_DEF("debug/settings/stdout/print_fps", false);
+	GLOBAL_DEF("debug/settings/stdout/print_gpu_profile", false);
+	GLOBAL_DEF("debug/settings/stdout/verbose_stdout", false);
+	GLOBAL_DEF("debug/settings/physics_interpolation/enable_warnings", true);
+	if (!OS::get_singleton()->_verbose_stdout) { // Not manually overridden.
+		OS::get_singleton()->_verbose_stdout = GLOBAL_GET("debug/settings/stdout/verbose_stdout");
+	}
+
+	register_early_core_singletons();
 	initialize_modules(MODULE_INITIALIZATION_LEVEL_CORE);
 	register_core_extensions(); // core extensions must be registered after globals setup and before display
 
@@ -1899,20 +1943,6 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 #ifdef TOOLS_ENABLED
 	if (editor) {
 		packed_data->set_disabled(true);
-		main_args.push_back("--editor");
-		if (!init_windowed && !init_fullscreen) {
-			init_maximized = true;
-			window_mode = DisplayServer::WINDOW_MODE_MAXIMIZED;
-		}
-	}
-
-	if (!project_manager && !editor) {
-		// If we didn't find a project, we fall back to the project manager.
-		project_manager = !found_project && !cmdline_tool;
-	}
-
-	if (project_manager) {
-		Engine::get_singleton()->set_project_manager_hint(true);
 	}
 #endif
 
@@ -1984,8 +2014,6 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 
 	Logger::set_flush_stdout_on_print(GLOBAL_GET("application/run/flush_stdout_on_print"));
 
-	OS::get_singleton()->set_cmdline(execpath, main_args, user_args);
-
 	{
 		String driver_hints = "";
 		String driver_hints_with_d3d12 = "";
@@ -2544,9 +2572,6 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 			window_vsync_mode = DisplayServer::VSyncMode::VSYNC_DISABLED;
 		}
 	}
-	Engine::get_singleton()->set_physics_ticks_per_second(GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "physics/common/physics_ticks_per_second", PROPERTY_HINT_RANGE, "1,1000,1"), 60));
-	Engine::get_singleton()->set_max_physics_steps_per_frame(GLOBAL_DEF_BASIC(PropertyInfo(Variant::INT, "physics/common/max_physics_steps_per_frame", PROPERTY_HINT_RANGE, "1,100,1"), 8));
-	Engine::get_singleton()->set_physics_jitter_fix(GLOBAL_DEF("physics/common/physics_jitter_fix", 0.5));
 
 	GLOBAL_DEF_RST(PropertyInfo(Variant::INT, "audio/driver/output_latency", PROPERTY_HINT_RANGE, "1,100,1"), 15);
 	// Use a safer default output_latency for web to avoid audio cracking on low-end devices, especially mobile.
@@ -2554,15 +2579,6 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 
 	Engine::get_singleton()->set_audio_output_latency(GLOBAL_GET("audio/driver/output_latency"));
 
-	GLOBAL_DEF("debug/settings/stdout/print_fps", false);
-	GLOBAL_DEF("debug/settings/stdout/print_gpu_profile", false);
-	GLOBAL_DEF("debug/settings/stdout/verbose_stdout", false);
-	GLOBAL_DEF("debug/settings/physics_interpolation/enable_warnings", true);
-
-	if (!OS::get_singleton()->_verbose_stdout) { // Not manually overridden.
-		OS::get_singleton()->_verbose_stdout = GLOBAL_GET("debug/settings/stdout/verbose_stdout");
-	}
-
 #if defined(MACOS_ENABLED) || defined(IOS_ENABLED)
 	OS::get_singleton()->set_environment("MVK_CONFIG_LOG_LEVEL", OS::get_singleton()->_verbose_stdout ? "3" : "1"); // 1 = Errors only, 3 = Info
 #endif
@@ -2578,15 +2594,6 @@ Error Main::setup(const char *execpath, int argc, char *argv[], bool p_second_ph
 		Engine::get_singleton()->set_audio_output_latency(audio_output_latency);
 	}
 
-	OS::get_singleton()->set_low_processor_usage_mode(GLOBAL_DEF("application/run/low_processor_mode", false));
-	OS::get_singleton()->set_low_processor_usage_mode_sleep_usec(
-			GLOBAL_DEF(PropertyInfo(Variant::INT, "application/run/low_processor_mode_sleep_usec", PROPERTY_HINT_RANGE, "0,33200,1,or_greater"), 6900)); // Roughly 144 FPS
-
-	GLOBAL_DEF("application/run/delta_smoothing", true);
-	if (!delta_smoothing_override) {
-		OS::get_singleton()->set_delta_smoothing(GLOBAL_GET("application/run/delta_smoothing"));
-	}
-
 	GLOBAL_DEF("display/window/ios/allow_high_refresh_rate", true);
 	GLOBAL_DEF("display/window/ios/hide_home_indicator", true);
 	GLOBAL_DEF("display/window/ios/hide_status_bar", true);
@@ -3013,10 +3020,9 @@ Error Main::setup2(bool p_show_boot_logo) {
 	}
 
 	// Max FPS needs to be set after the DisplayServer is created.
-	Engine::get_singleton()->set_max_fps(GLOBAL_DEF(PropertyInfo(Variant::INT, "application/run/max_fps", PROPERTY_HINT_RANGE, "0,1000,1"), 0));
-
-	if (max_fps >= 0) {
-		Engine::get_singleton()->set_max_fps(max_fps);
+	RenderingDevice *rd = RenderingDevice::get_singleton();
+	if (rd) {
+		rd->_set_max_fps(engine->get_max_fps());
 	}
 
 #ifdef TOOLS_ENABLED
diff --git a/platform/windows/os_windows.cpp b/platform/windows/os_windows.cpp
index 984c9ae90e3..2b5c77d4b93 100644
--- a/platform/windows/os_windows.cpp
+++ b/platform/windows/os_windows.cpp
@@ -1528,7 +1528,8 @@ DWRITE_FONT_STRETCH OS_Windows::_stretch_to_dw(int p_stretch) const {
 }
 
 Vector<String> OS_Windows::get_system_font_path_for_text(const String &p_font_name, const String &p_text, const String &p_locale, const String &p_script, int p_weight, int p_stretch, bool p_italic) const {
-	if (!dwrite2_init) {
+	// This may be called before TextServerManager has been created, which would cause a crash downstream if we do not check here
+	if (!dwrite2_init || !TextServerManager::get_singleton()) {
 		return Vector<String>();
 	}