In regards to email aliasing services, addy.io is the only one I know of other than SimpleLogin, which is owned by Proton AG--so if you want to get away from Proton, SimpleLogin isn't an option. Both of these services are recommended on privacyguides.org.
Some email services allow you to use a domain you own, which theoretically should give you unlimited aliases to work with, but may not be as privacy-focused as the email address is only as anonymous as your registered domain.
Personally, I prefer the 'pseudonymous' aliases that addy.io and Proton Pass give (it's usually something like random.words123@passmail.net
in the case of Proton).
If anyone has good experiences with other aliasing services that provide this option, please let us know.
This is excellent news. This is one of the biggest features that I've wanted out of Firefox for years, and one of the reasons I've kept Chromium as a secondary browser all this time.
I do remember seeing a community-made GitHub project that added a profile switcher to Firefox, which looked pretty good, but it also required installing an executable somewhere on the system, which I'm not exactly keen on.
I think Zen Browser has a built-in profile switcher, but it also changes a bunch of core UI elements... I just want Firefox with a profile switcher, lol.