I'm not worried about data loss. Honestly, the only feature I actually care about from sync is open tabs and recent history, since I'll often open something on one device that I was using on another. I don't really use bookmarks or saved passwords.

My main concern is security. I don't want my machines to be susceptible to malware, and with browsers being very complex, I want to make sure the dev team is very responsive in shipping security updates.

The main reason I use IronFox on my phone is that it works with FDroid, which is important because I don't have Google Play running on my main profile (I use GapheneOS). If the flatpak is updated within a few days of Firefox consistently, that's good enough. But if it takes weeks or more, that's too much.