I wonder where those clever boys hid it on the Mac version...
Yes. MC's HKCU registry keys are duplicated on Mac here:
~/Library/Application Support/J River/Media Center 20/Settings/User Settings.iniIn fact, this makes it easier to reset the OSX version of MC to defaults than it is on Windows, because you can just
delete or move that file. On Windows, you have to uninstall and tell it to remove Registry settings, and then reinstall.
By the way, it is worth mentioning: If you're mucking about, the
other file in the same directory, Machine Settings.ini will not really contain anything of use. This replicates the HKLM registry hive on Windows, and isn't relevant to basically anything you can set on MC directly, or that is worth mucking with.
And, remember, a Library Backup contains both, so it the easiest way to make a backup is to make a Library Backup, and not manually.