Just wanted to share my experience as someone that just updated to a p8p with GrapheneOS.
This is the first time I install a custom ROM in a smartphone and it hasn’t been easy but I’m pretty impressed so far. I installed their sandbox Google Play/Services to keep using banking apps and other apps that need it. Everytime I install an app it asks if it should have internet access permission so I can use Gboard without the need to use NetGuard.
I can limit storage scopes for every app. If I want WhatsApp to only be able to access my Downloads folder, I can. If I want to trick it saying that it has access to my contacts, I also can.
The biggest issue for me now is probably install/use things in a way that just don’t throw all the OS purpose out of the window and without asking questions considering how awful people can be when they think a question is dumb.
I was a bit disappointed with the lack of microSD but I realized I probably wouldn’t use it. I also had to install a custom launcher to customize icons and such.
One thing that worries me is how to setup a way to find my phone in case I lose it.