We are all still here because we want to know hw model and Os that Brito is using in real life, it would be really nice to know. So we cam evaluate if it's a better solution compared to Pixel/graphene combo.
Discussion
All depends on your security model and needs. Just because I point some obvious hardware flaws, doesn't mean I need to use them myself.
I'm the kind of guy that writes embedded operating systems on dedicated hardware and networks just to know in detail what is used. Even there exist exploits to be aware.
For example, Wi-Fi chips cannot simply be trusted and the alternatives are still expensive: https://archive.fosdem.org/2021/stands.fosdem.org/stands/openwifi/
It is a long and lonely road without fame nor profit. You are welcome to join if you are interested on the topic.