UserDefault on Mac

I started using UserDefault to save my settings, and they work great on Windows, and they seem to work great on my own Mac, but multiple people who bought the game are having problems that the Windows people aren’t. It seems tied to a user setting, but I don’t know how to view it, since I can’t find the UserDefaults.xml file. I didn’t realize that it’s implemented differently on Mac than on Windows. I’d like them to be able to directly view and even edit the user preferences file, like I can do on the Windows version.

Any suggestions? Thank you.

[Update: I just noticed there are UserDefault and CCUserDefault, which do I use?]