If they open source it and everyone can verify that the code only stores your “identity” locally and doesn’t/can’t share the data, you get pretty decent privacy protection while preventing your kid from using a firearm without permission/supervision. If you zoom out 30-50 years, I bet most firearms employ this tech.
The right move - in my opinion - is getting it implemented in a way that respects the rights of the average person, and also has a measurable impact on reducing the horrific stuff that happens when powerful weapons fall into the wrong hands.