You could set up a Firefox Account and use Firefox Sync to synchronize your Beta and stable profiles (and then disable Sync or the account, if you like).
I'd do that, but sync misses things like container settings. Also, I'm unable to run stable at all. Whenever I install and run stable, I somehow end up with the beta version.
That's great news. I have sync enabled already. The only remaining problem is that I can't seem to install the stable release. Whenever I download it and run the executable, it just starts up immediately in beta again.
