If you have a FP3, did it never fall down, throwing its battery out? I had that happen a few times to me in the past and I always wished for a tiny bit more "grip" on the battery. I would guess that I'm not the only one.
I've bought the FP3+ camera, and I'm on my third battery pack, degoogled with murena /e/-OS. Works perfectly, except the screen is a little too large for me. I wish it was a Sony Xperia ZX1 compact size, but one can't have it all.