I liked the community challenge! It was simple and cute, and I think that was a good choice. :)

I still prefer character matching only for this exchange, for the reasons snickfic, kimaracretak, and others have listed. I personally felt less into looking around for treats when I'd need to sort through all the relationship requests instead of going "I wanna write about X character, who's interested in them?". I don't mind writing relationships, but I find it easier to treat when I'm not locked into any specific relationship. (Especially since almost every other exchange does relationship matching!)

Also, I see people talking about the timing of reveals. I have zero problem with when reveals currently are, but tbh I really have no feelings about when reveals happen so long as the reveals time is clearly stated. (And, especially for a long-running exchange like this, any change in that time is mentioned well in advance and highlighted for people running off habit.)