[Marcello]

"Sand berms, sounds, walls and cosmetic enhancements are not beyond the game engine. The existing terrain and OOB features suggest that much."

Likely. Unless there is some limitation sand berms, for example, could replace hedgerows in the desert menu like it happens for many others terrains.

"To make for SAM, SP-SAM, etc. shooting by a volley (some rockets from one unit shoot at the same Turn).
But, that cost unit strongly did not increase."

Can you try to explain what you are saying? As it is I do not get what you mean.