The kerbal planets are already so big that there is nothing interesting on 99% of the surface area of them. There are mods to make them "full sized", but they

The kerbal planets are already so big that there is nothing interesting on 99% of the surface area of them. There are mods to make them "full sized", but they don't make the planets less interesting than they were otherwise. Really the planet size in that game is about game balance.