Looking at deploying Python via Intune Company Portal which appears to stop the installer from adding items to the environment path. Using PSADT to run a post install script should work for the installation location e.g. C:\Program Files.… but doing the same for %AppData%\Python.… does not appear to get translated into C:\Users\username\appdata.… in PowerShell/Terminal e.g. $env:path shows ‘%appdata\Python.…’ rather than the full path.
I think I want to add the %appdata% path to System so as it’s there for all existing and future users (if that’s possible).
Look like there is specific install syntax to install Python for all users.
Although this is an old article (and for an older version of Python), but it looks like it has some clues for an all users install: