Make a backup and save it.
You can reinstall stock if you don’t like it.
Grapheneos is just a normal OS. You can’t do everything, like google pay or face unlock (because it’s too insecure) but 99% works just like any other android phone.
Installing the os doesn’t take too much time.
It’s always funny to me when people wave away tap to pay like losing it is nothing.
It’s my number 1 practical use case for my phone. My commuter card is stored there for example. I use it as often as I take photos at this point: I might take a dozen photos on the weekend but I commute every day.
For me tap to pay is useless, I always carry my cards.
If you wanna use a physical metro card that you have to refill with cash every X rides be my guest.
Horrid experience, I’ll keep my tap thanks