After reading through the thread, random thought just hit me that they should just add another world/data center like they did with Shadow DC on EU. World added on OCE that noone can create a character on/home world transfer to, but exists as extra zone space and therefore doesn't affect login queue/local population. I saw a few posts on twitter about people wanting to do different themes of the same type of event so other/different zones could be capped in the future so just adding extra Costa instances even if possible (not sure if they can add it just for 1 world and not have to toggle it globally), isn't a permanent solution to the problem.