If anyone ever comes up with a smart gun system that's 99.8% accurate, that will, no doubt, be good enough. Pity no one has yet, and no one is likely to any time soon. Biometrics just aren't there yet, despite improvement in recent years.
As to the rest, if you expect otherwise, you're a naive fool. Especially if you think that somebody is going to replace a critical piece of equipment with a - as you note - 99.8% success rate with one that is, at best, an order of magnitude lower (which 99% is, and last I heard, nobody could manage that with smart guns, either, in the real world.) It's rare to see any biometric ID system exceed 80% in real world conditions.