I think the only possible issue is due to Windows, not V4 or Poser.

Poser 5 still had the runtime in the Poser folder, in Program Files. As I recall, that caused issues when you tried to run that .bat file to initialize V4's morphs, since newer versions of Windows have Program Files locked down like Fort Knox.

As long as V4 is installed in a runtime that's not in Program Files, it should be fine.