Well, I am happily using mac keyboards on Fedora. Coming from a mac, the most important tweak for me was to swap the Ctrl and Cmd keys (that is, to continue using the thumb instead of pinky finger for the Ctrl+[Some-Letter] key combinations. The easiest way to do this is via GNOME Tweaks: Keyboard → Additional Layout Options → Ctrl position
The rest of customization can be easily obtained via keyboard shortcuts. No need to alter system-wide xkb config files.
If you’re referring to the use case of having two different keyboards with separate keyboard setups, this is the post describing one possible solution: