Obtainium has been my go to for open source for many years now. You don't want to be relying on fdroid when you can add direct from source code releases. Up front config required but can backup and restore easily after that. Zapstore coming along nicely but not as flexible and doesn't have all the apps you want yet. Aurora store for the handful of proprietary apps you might still need or are in the process of transitioning out of.

Obtainium stack

Easy to install indeed but how to ensure the different profiles are indeed “sandboxed” and safe for use (no tracking) It’s also difficult to have both an esim and sim installled for different profiles

Welcome. You will love it. I prefer it over an iphone after several years of use. Lots of settings options too. I like one that switches wifi off when it disconnects from the netowork for more than a minute. I prefer the manual reuqirements to allow the phone to do things. Lots of permissions controls.

Have you figured out how to do this? Still not managed it myself.

I learned to ignore all proprietary apps/appstores. Can absolutely recommend the feeling of freshness and ease