Mongo is appalled!

UPDATE - looks like chezmoi MIGHT handle this https://www.chezmoi.io/reference/templates/functions/mozillaInstallHash/. Haven't found a working example of it in use though

I just look for the folder with -release on the end

    PROFPATH=$(grep 'Path=' $HOME/.var/app/org.mozilla.firefox/.mozilla/firefox/profiles.ini | sed s/^Path=// | grep release)

I think this will hit the same problem - the profile folders are named differently every install. While you could theoretically back up the whole folder there are references inside that would break if you used it on different systems

FF sync doesn't cover everything, in particular toolbar setup. There is a user.js file you can create that plugs the gap but this hits the exact problem (picking the right folder) the OP stated

Splitter!