I have modded the base Management .pk3 file to set the base as I want from initial startup, I had played the original base defence battle many times and was interested in having a different setup, mostly to allow variety but also to allow some of the advantages of the different buildings to be recognized in the mostly frequently attacked base.
I would be keen on a price multiplier on the structure costs depending on ground status. E.G. blue rock 1/2 price building, red rocks 1x price buildings, green rocks 2x price buildings, brown rocks 3x price buildings. Of course, to make this more logical the different areas of the world would have to have various setup costs according to location, e.g urban base very expensive and hard rocks, mountain base very cheap but hard rocks, silt base on flood plan - very expensive but no rocks. A hovering tooltip on the geoscape would give you a heads up of what to expect.
These variables may also be of advantage to further projects also. Terror from the deep....