To be fair, "it just works" is a relatively recent feature of Graphene. It used to not be able to support things like Uber, Google Maps, etc.

And, I still haven't been able to get it to properly support Google Fi, wherever I switch profiles it confuses the carrier and my access gets reset.

My solution has been to have two phones, one with Google Fi that I use to hotspot my Graphene device. Everything else seems to work fine on Graphene, including Uber and maps and calendar and VPNs and isolated profiles for gaming vs work vs socializing, etc