Thank you, @pmoody, for the suggestion. There are many strategies. What you outline would, with some investment in time, deliver what I want for ´mom and dad’. But it would lack the /e/ eco system (email, online storage, backups, safe search). I prefer to stay on the /e/ track and reap the benefits, now and even more in the future.
Your suggestion makes me think again. Lets presume ‘mom & dad’ (or other non-technical relatives or friends) agree to start using an /e/ phone. If I disable MicroG on their phone, I can be pretty sure it will stay that way. Might still be good to check this out from time to time.
LineageOS can be set up without the Google core services, and it has a suite of apps that are independent and almost all the apps installed are open source (I think there are a couple non open-source, and many of the apps are made by Lineage developers). So while the email app isn’t forked from K9, it is forked from something else, as are all the other apps.
I am on /e/, my wife is on LineageOS sans Google.
Whatever works for you, eh? It sounds like your solution would work for your family/friends, and since you are on /e/, you could better support them. Win-win.
Oh, it was a hard way to get it running and as you can read in the post above, no one really knows if enabling spoofing is good or not. On my devices it has changed nothing.
With this script and patch you can get it working (I hope nothing changed in sources)