evileeyore:
I've had several interactions with someone in a game as Players who was just... untenable to play with...<snip>...I have no idea who they are outside of two Character names they've used.
I have no idea if they are running games...<snip>
I dealt with this exact situation in the last couple of months.
Player in a game seemed fine; in fact he decided to GM a game, and I joined. This his behaviour crossed a line for me. I left both games (elegantly, IMO. In both cases, I stuck around and actively posted until the party got to town, and them my character and I took our leave.)
Many weeks later, I applied for a game, GM looked great, group was active, all-in-all, it looked like it would be a great game. Once I was given access, I saw that old player there - and I only knew because he used the same character name. I apologised to the GM and left before I started.
Keeping a list of GMs is easy, and I suppose if you are the GM, a list of the players is also easy. But as a player, tracking other players is impossible. As EvilEyore says, it is a frustration and not overly important, but if we are voting, I would vote for this feature too.