Regarding Bloody's idea, at the point it would have been a good idea, except for a few things:
1. We do have not only one but two extra slots, in addition to KHC and KR. K1 is unplayable so that even INVICTRA & CO aren't playing anymore on it. I guess it could b fixed somehow by deleting regions or something, but this might need some time to do. K2 has been empty for months. If we were to consider this kind of thing it could be run on the same server, and it would be less administrative work to maintain.
2. I'm just serving as Arch's representative while he is gone, and can't make a drastic decision like this in his absence without consulting him that would spread out the playerbase in this way from his server.
3. I'm skeptical about RTG as well, since there are still issues with the biome transitions, which makes it look rather ugly, and I acknowledge there are points with Ishi's criticism, however I remain hopeful that it could turn out better in future releases, but I don't have any time estimates or know if these issues will ever be fixed. As such this could well mean that all would remain playing on ATG indefinitely.
Lastly, after some experimentation during the weekend we have come up with an CC + ATG + Extra biomes configuration that solves most of the problems I had with KHC worldgen, for instance the lack of decent looking mountains. The lack of oceans is still a problem though. But anyways, it turned out rather satisfactory IMHO. I'll upload the scripts and configs and post the full modlist when I come back from work so you can have a look.