diff --git a/CMakeLists.txt b/CMakeLists.txt
index 351a209c45..e975e2c33c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -172,14 +172,19 @@ include(px4_add_module)
 set(config_module_list)
 set(config_kernel_list)
 
-# Find Python
-find_package(PythonInterp 3)
-# We have a custom error message to tell users how to install python3.
-if(NOT PYTHONINTERP_FOUND)
-	message(FATAL_ERROR "Python 3 not found. Please install Python 3:\n"
-		"    Ubuntu: sudo apt install python3 python3-dev python3-pip\n"
-		"    macOS: brew install python")
+# Find Python. The call below sets Python3_EXECUTABLE; we then provide
+# PYTHON_EXECUTABLE as a backward-compat alias for the rest of the
+# codebase that still uses the legacy name.
+find_package(Python3 COMPONENTS Interpreter REQUIRED)
+
+# Preserve PYTHON_EXECUTABLE as passed if any (e.g. via -D on command
+# line, or from the top Makefile); or else default to what
+# find_package(Python3) resolved. Promote to a CACHE FILEPATH entry so
+# cmake -L lists it, to avoid spurious reconfiguration.
+if(NOT DEFINED PYTHON_EXECUTABLE OR PYTHON_EXECUTABLE STREQUAL "")
+	set(PYTHON_EXECUTABLE "${Python3_EXECUTABLE}")
 endif()
+set(PYTHON_EXECUTABLE "${PYTHON_EXECUTABLE}" CACHE FILEPATH "Python 3 interpreter" FORCE)
 
 option(PYTHON_COVERAGE "Python code coverage" OFF)
 if(PYTHON_COVERAGE)
diff --git a/cmake/kconfig.cmake b/cmake/kconfig.cmake
index e483ee6f0e..45fb7bd1fc 100644
--- a/cmake/kconfig.cmake
+++ b/cmake/kconfig.cmake
@@ -44,6 +44,10 @@ if(EXISTS ${BOARD_DEFCONFIG})
 			OUTPUT_VARIABLE DUMMY_RESULTS
 		)
 	else()
+		# Non-default labels merge default.px4board + {label}.px4board,
+		# so reconfigure must also trigger on changes to default.px4board.
+		set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS ${PX4_BOARD_DIR}/default.px4board)
+
 		# Generate boardconfig from default.px4board and {label}.px4board
 		execute_process(
 			COMMAND ${CMAKE_COMMAND} -E env ${COMMON_KCONFIG_ENV_SETTINGS}
diff --git a/cmake/px4_config.cmake b/cmake/px4_config.cmake
index e1ab6e5545..ee63a4f39a 100644
--- a/cmake/px4_config.cmake
+++ b/cmake/px4_config.cmake
@@ -41,6 +41,11 @@ if(NOT CONFIG)
 	else()
 		set(CONFIG "px4_sitl_default" CACHE STRING "desired configuration")
 	endif()
+else()
+	# Promote CONFIG from UNINITIALIZED (set by -D on command line) to STRING
+	# so that cmake -L lists it. The Makefile's cmake-cache-check relies on
+	# finding CONFIG in cmake -L output to avoid unnecessary reconfiguration.
+	set(CONFIG "${CONFIG}" CACHE STRING "desired configuration" FORCE)
 endif()
 
 if(NOT PX4_CONFIG_FILE)
diff --git a/platforms/nuttx/NuttX/CMakeLists.txt b/platforms/nuttx/NuttX/CMakeLists.txt
index f28ea9fdb4..3a700ce9ff 100644
--- a/platforms/nuttx/NuttX/CMakeLists.txt
+++ b/platforms/nuttx/NuttX/CMakeLists.txt
@@ -144,15 +144,22 @@ file(GLOB_RECURSE nuttx_apps_files LIST_DIRECTORIES false
 	${APPS_DIR}/*.c
 	${APPS_DIR}/*.h
 )
+
+# Exclude generated builtin headers - they are regenerated by the apps
+# build from registry files and would create a perpetual dirty cycle
+# if tracked.
+list(FILTER nuttx_apps_files EXCLUDE REGEX "builtin/builtin_list\\.h|builtin/builtin_proto\\.h")
+
 add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/apps/libapps.a
-	COMMAND ${CMAKE_COMMAND} -E remove -f ${APPS_DIR}/libapps.a ${APPS_DIR}/builtin/builtin_list.h ${APPS_DIR}/builtin/builtin_proto.h
-	COMMAND find ${APPS_DIR} -type f -name \*.o -delete
 	COMMAND ${CMAKE_COMMAND} -E copy_if_different ${CMAKE_CURRENT_BINARY_DIR}/px4.bdat ${APPS_DIR}/builtin/registry/px4.bdat
 	COMMAND ${CMAKE_COMMAND} -E copy_if_different ${CMAKE_CURRENT_BINARY_DIR}/px4.pdat ${APPS_DIR}/builtin/registry/px4.pdat
 	COMMAND ${CMAKE_COMMAND} -E touch_nocreate ${APPS_DIR}/builtin/registry/.updated
+	COMMAND ${CMAKE_COMMAND} -E touch_nocreate ${APPS_DIR}/builtin/builtin_list.c
 	COMMAND make --no-print-directory --silent TOPDIR="${NUTTX_DIR}" > ${CMAKE_CURRENT_BINARY_DIR}/nuttx_apps.log
 	COMMAND ${CMAKE_COMMAND} -E copy_if_different ${APPS_DIR}/libapps.a ${CMAKE_CURRENT_BINARY_DIR}/apps/libapps.a
 	DEPENDS ${nuttx_apps_files} nuttx_context ${NUTTX_DIR}/include/nuttx/config.h
+		${CMAKE_CURRENT_BINARY_DIR}/px4.bdat
+		${CMAKE_CURRENT_BINARY_DIR}/px4.pdat
 	WORKING_DIRECTORY ${APPS_DIR}
 	#USES_TERMINAL
 )
@@ -175,8 +182,6 @@ function(add_nuttx_dir nuttx_lib nuttx_lib_dir kernel extra target)
 	)
 
 	add_custom_command(OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/nuttx/${nuttx_lib_dir}/lib${nuttx_lib}.a
-		COMMAND ${CMAKE_COMMAND} -E remove -f ${NUTTX_DIR}/${nuttx_lib_dir}/lib${nuttx_lib}.a
-		COMMAND find ${nuttx_lib_dir} -type f -name \*.o -delete
 		COMMAND make -C ${nuttx_lib_dir} --no-print-directory --silent ${nuttx_lib_target} TOPDIR="${NUTTX_DIR}" KERNEL=${kernel} EXTRAFLAGS=${extra}
 		COMMAND ${CMAKE_COMMAND} -E copy_if_different ${NUTTX_DIR}/${nuttx_lib_dir}/lib${nuttx_lib}.a ${CMAKE_CURRENT_BINARY_DIR}/nuttx/${nuttx_lib_dir}/lib${nuttx_lib}.a
 		DEPENDS