I’ve been working on switching from macOS to Linux. I tried moving my Firefox profile (actually Zen Browser but I don’t think it makes a big difference) but it was very laggy when opening, and addons didn’t work. So I’m just gonna do it the safe way: exporting my session with Tab Session Manager, places.sqlite file (which contains browsing history), bookmarks, addon data, and using syncing. I’m wondering how well copy and pasting the profile folder between OSes worked for other users.
Honestly, I just signed into Firefox sync (or whatever it is called), forced a sync, done. Moved from Windows to Linux in about ten minutes. Most of which was me being super cautious and checking and triple checking before and after. 10/10 would sync again.