Playing in a 10-12 prov kd has proved up there with some of the most fun I've had in Uto for a while.
While kds only half filled seem to be assumed to be ghetto, I actually think it strengthens all the good things about utopia - teamwork and communication, complementing each other's province strengths, strategy (less room for error).
I was going to suggest a two-tier server, one with small kds who can graduate and merge to full 25 provs but I don't really like that.
Instead, make the whole server a cap of 12 prov kds. Want more provs? Pay a premium tax to the overlords for more spots....
Happy to hear why this isn't good, so long as its not just "that's not how we always did it".