ALLUSERS=1 implies that installation always happens in a per-machine
installation context. However, when updating the PATH additional flags
are required to ensure that the system environment is updated as per
A package that is used for installation in the per-machine
installation context should write environment variables to
the machine's environment by including * in the Name column.
This is in line what CPython uses when generating the official MSI installer:
@Anthony Tuininga: any update?
Apologies for the delay. Your pull request looks reasonable to me! So it is now merged.