In the end I went with none of the 3 OS options I mentioned before. It turned out that Sailfish isn’t available or actively developed for the FP3. I was going to go with e/OS but the GUI installation tool came in a snap package for Linux and I don’t know how to install snaps on my openSUSE distro, whilst the command line method didn’t sound like it would be so friendly. I never got into looking at Lineage OS before I stumbled across a couple of reddit posts mentioning another alternative based on Lineage, iodéOS.
Since it focuses more strongly on privacy controls and a privacy-oriented default selection of apps, almost entirely de-Googled, it sounded enticing. What’s more, it’s developed by a team in Toulouse but with French and English documentation, and with me living in France that also appealed. The install instructions however were far too vague and brief and I needed to hunt down some missing steps and ultimately fiddle at least as much as I would have done with the CLI install method of e/OS.
After a couple of scares where I thought I’d messed up and bricked the phone, I got it installed and have been testing it with my lesser-used backup SIM in preparation for inserting my main SIM in the 2nd slot and switching over fully. So far so good. A few niggles with certain default apps which don’t have the necessary permissions to do fundamental things, like the Magic Earth navigation app not having access to GPS by default, so some things need tweaking. The iodéOS version for the FP3 is based on Android 11 so at the time of writing that puts it one rung up compared to the Android 10 offering on the standard Fairphone install. I found that stock Android install depressing to look at on the brief moments I spent with it, not least that irritating bouncing Google search bar on the home screen. I was absolutely desperate to get everything Google off my phone and iodéOS has done that rather well. Just updated from v2.3 to v2.4, which went smoothly and only required a reboot. Only installed one app thus far, KDE Connect, which provides almost seamless integration with my Plasma desktop. Kool!