The narrow scope of this issue could be implemented by defining a scheme for local builds in the PythonCore key -- such as "X.Ys[-32]". The build process would create or update the "HKCU\Software\Python\PythonCore\X.Ys[-32]\InstallPath" key with the "ExecutablePath" and "WindowedExecutablePath" values. 

In PC/launcher.c, validate_version() would have to allow "s" after the major/minor version (e.g. "3s", "3.10s"), and locate_python() would have to ignore "s" when deciding to call get_configured_value(config_key) if no minor version is specified (e.g. for "3s", check PY_PYTHON3 and the "python3" value in py.ini).