There should just be a way to setup an alternate dummy account based on the finger you use. This gives the illusion of compliance but your real data is safe.

If you're in a situation where this is a pressing issue, it's not a good solution as it's trivial to detect if it's a fake environment, especially if they get suspicious and run external forensics on it.

iirc the GrapheneOS team won't implement this feature for that reason

The middle finger could be the emergency use one ...