One thing that is a game changer on GrapheneOS is the network toggle for apps. Turn off network access for your keyboard, camera app, calculator, files, etc.
That's not at all a similar approach so it doesn't quality as "if anyone wants *this*). The GrapheneOS feature pretends the network is down and local host is also inaccessible. This is good for compatability (apps generally take into account that a network can be down) and too avoid apps knowing you are using the feature.
