Mozilla stated that a while back.

How do I capitalize Firefox? How do I abbreviate it?

Only the first letter is capitalized (so it’s Firefox, not FireFox.) The preferred abbreviation is “Fx” or “fx”.

#8 in the FAQ

You’re right, it doesn’t. That does give me an idea though.

You could use overlayfs with an opaque upper directory to hide the files littering your $HOME and still access them by bind-mounting them into the appropriate xdg dirs.

Way more effort than it’s worth, of course.