This mod increases the maximum number of heighttypes you can have on a savegame. By default, a maximum of 63 heighttypes are possible, this mod increases the number to 256.
Of course, it should be noted that the limit was not set for no reason and that a large number of heighttypes can lead to a drop in performance, especially if they are all active at the same time.
So everyone has to find out for themselves how far they can push this on a corresponding savegame.