grave hazel
.name <name> issues in the chat will give you names that a player has used earlier on.
It could be .name or .namemc (or such). It is the best way i can think of doing it (if it should be integrated into Lunar). It would be way easier than going to namemc and searching for a playername there.
Labymod has had it, I dont know if they still do, but it is possible.