Really, I'd rather see a lock option on bio-metrics. Use my right index finger and it unlocks. Use my thumb and it disables all bio-metrics. Since cops can make you press your finger to the pad (in the US and a few other places), make it so it deep locks the phone if use use the "wrong" finger.
I'd set it to unlock with my middle finger and deep locks with either of my index fingers, or my thumbs. Even allow different pins when in deep lock.
Useless gimmick. What Android needs is emergency lock/shutdown/wipe. Like usable during swat raid. Or the phone is taken away from you by force. Lock removes biometrics while locking. Shutdown - shuts downs the phone. Wipe reboots and wipes everything.
3 days are more than enough to have the pin beaten out of you and if you are infected by NSO - more than enough for the agent to upload everything to their servers.
There are many models in which you may only have seconds to make the phone totally locked without biometrics. Or the phone to be a meter or two away from you.
I'd set it to unlock with my middle finger and deep locks with either of my index fingers, or my thumbs. Even allow different pins when in deep lock.