Well, for my use the 32bit version works fine (only the 32bit version supports modern skins). When I upgraded my PC from Windows 7 to Windows 10 back in 2019, I never reinstalled Winamp and just installed WACUP on it. There are features I use in WACUP that are built into it that Winamp required particular plugins that are no longer around (the HTTP Post stuff).
Anyway, the best advice I have is probably to just try it. The 32bit version is the one I would try first and make sure if you do install it, to place it into its own program directory like "C:\Program Files (x86)\WACUP" and NOT on top of your Winamp installation so that it remains untouched. That way you can play with it and not muck up Winamp.