This has been suggested several times (several posts refer to it) and a majority of active players support it. Maybe you could implement it some kind of way @Admin @GameOperator
If not possible to add a working feature at the event NPC, you should consider logging often to offer this service to players.
It would boost the usage of in game materials (GT, Manuals, Golds, stones), but also the usage of EC (which means obviously more money for the owning part of the server) through the cloak rerolls and wing chests (because people are going to try chasing for their favorite wings).
+1 again. Very nice suggestion.