I think the Contest Hall would be an interesting idea for RP. Perhaps it could work in conjunction with the happiness scale? Though, Return and Frustration don't rely on Happiness in ASB, it could be a good way to create better flavor. Also, it could work with Attract too, so if your Pokemon win more and get more items that make it more appealing, Attract will become more "powerful" in a sense.
Anyways, good idea, I look forward to it being implemented (assuming it does).
This week's Avatar is from:
Zetsuen no Tempest