Edit:. Yep, I just checked in-game. When creating the world, I saw the huge logo of the mod, and I clicked It. I barelly could pick wiselly what kind of base It would generate, because It had a counter until the generation step of the base reached.
My idea would be to when the player is still selecting a base, the game waits before generating the base, until the player closes the interface (Yep, a button to close It would be cool too).
I ask that, because It may seem like there's enough time to pick the styles, but for people like me, the fact that there's a "timer" running, causes a kind of panic, so I picked granite and a random style of base to spawn.