I found rpg.actor while looking to see if anybody had done character sheets on ATProto. I really like the work they’ve put into it but they use a static “self” key to make it 1 character per identity/account. That makes a ton of sense for the character-heavy kind of play (like 5e) that it looks like they’re aiming for. I mostly play Cairn and similar games though where characters are a bit more transient. Although they do support DCC which kind of straddles those two worlds