Okay, I just tested switching to the NuGet package and appear to have hit some sort of issue:

C:\myproject\tools\windows\.python-win\python\tools\python.exe: No module named venv
Traceback (most recent call last):
  File "C:\myproject\tools\windows\\windows-build.py", line 129, in <module>
    do_build()
  File "C:\myproject\tools\windows\\windows-build.py", line 60, in do_build
    ".python-win", "spen-venv")
  File "C:\myproject\tools\windows\.python-win\python\tools\Lib\subprocess.py", line 395, in check_output
    **kwargs).stdout
  File "C:\myproject\tools\windows\.python-win\python\tools\Lib\subprocess.py", line 487, in run
    output=stdout, stderr=stderr)
subprocess.CalledProcessError: Command '['C:\\myproject\\tools\\windows\\.python-win\\python\\tools\\python.exe', '-m', 'venv', 'C:\\myproject\\tools\\windows\\.python-win\\spen-venv']' returned non-zero exit status 1.

Is this expected with the NuGet variant? Can I somehow install 'venv' on top? I didn't have this issue with the install obtained by running the Windows Installer with /Q