I think this may already be happening, sorry if it is, but as of now it's impossible to get clothes from missed events/ packages (which is a big problem as both a newcomer and someone who really like sailor/pirate themes. You could probably use a similar thing to the token trading (but then again, I'm not a programmer)
speaking of tokens, I think that, after the event, tokens should be able to be placed on eldsonas as accessories. They wouldn't need an art change, you could just kinda. throw them in somewhere. Sorry to put more work on you -_-
~Roe!