> By default KeyBox will overwrite all values in the specified authorized_keys file for a system.

This honestly seems like a terrible default. I want an explicit something when I'm about to lock myself out of my systems.

OTOH, the prerequisites are substantial enough that you're hardly likely to install it by accident. I suppose it's a better fit for brand-new hosts on both fronts. (But then, as I see it, all the hard parts around key management are around getting it reliably deployed across the entire system, which means also on old, long-running boxes. If we could all wipe our prod infra and start again from read-only media ((which we should probably do more often, to the extent that circumstances permit)) it wouldn't nearly as hard of a problem.)