Ah, now I understand the miscommunication. Point is the technology, the phone, the FaceID, are immaterial. The ultimate goal is the protection of people. Having evidence of wrongdoing by government agents is important, but it is a means to the ends of a just and equitable society free of folks willing to use their position to abuse you.
The coercion of FaceID is always secondary to the abuse of people. Fixation on the security measures being subverted misses the overall point.
Yep, the 4,096-bit RSA will be enough to protect you from a rogue cop.