B: Not worth it.
Keys are overrated in Coincidence anyway.
Sure, you need them to communicate with the server, and other people.
But just for this any pair of keys is good enough.
And the keys are not related to usernames.
You can set whatever name you want.
By default, the client doesn't show key fingerprints of other people.
So It's easy to pretend to be someone else.
Because nobody is looking at the keys to check who is who.
So I'll just set my name.
KXA: But you must do it!