I'm imagining that I'd just use whatever grapheneos keyboard, or Florisboard, which I prefer for peck typing over Gboard.

My only problem is finding a time to switch. I need my phone for work, so I need to sit down, backup my data, install GOS and restore, then spend like 5 hours learning the new systems. Things like sandboxing Google are nice until I'm lost in BFE without Google Maps or OSMand+ because I didn't properly set up.