Yes, you are correct - but google services are still needed if you want to hail an Uber for ex amongst other things.

So daily driver with CalyxOS.

Bitcoin phone with GrapheneOS.

This will give me better piece of mind if I do have to use a hot wallet for a variety of reasons, but that's not my main goal with it.

First goal, is to accomplish a geographically separated multisig by visiting each cosigner with the Graphene phone, signing the PSBT at each location.

This should improve multisig convenience 1000x.

Second goal, is to connect my mobile wallet(s) to my full node - again improving convenience 1000x.

Third goal, is to store all sensitive data that needs to be stored digitally on the phone.