I wanted to leave this as a comment but there is a 1000 character limit and I went past that slightly!

This was to address the question: Why not just play vanilla Cydonia.

As for why this is preferred to a vanilla Cydonia. The folks I play this with all dislike the large amount of resources the MAV has when you come down. Starter equipment and food/water are great and all. But we generally try to avoid actively using the MAV when able.

This is largely due to the fact that the MAV seems to not reflect actual consumption of resources.

You drink 2 liters of water, the tanks stay as full as ever. There is no power aspect to the MAV. It just seems to run constantly without need of solar or methane fuel. Once you get crops going in it, it is essentially provides free food to. The MAV basically makes it so resource procurement and management is just not very important. Though these things could be oversights by the developer that get fixed later on.

There are also some complaints about the MAV itself causing FPS issues. This could partly be due to its size and the fact that there is an escape vehicle and gantry on it. Things that most people would probably be more than happy to have missing to save on rendering power.

A scenario a friend of mine and I have been contemplating is starting with a Mobile Lab instead of a MAV. The Lab could be out of (or very low on) Methane and limited on its ability to relocate. It does provide a cot and suit holders for replenishment of oxygen. It also allows processing of samples as well so you can check resource levels. I've been fiddling around myself seeing if I can get it going, no luck just yet though!

Hope the thoughts help and are along the lines of what you were looking for.