Can XCM be scrapped? If so, how many materials could we get back at maximum?

Not sure how I feel about a new type of installation being added just to handle captured CMCs, but it sure beats having to pay enemy civilians after you conquer their stuff! I definitely agree with making them less efficient than automines though.

It also makes me wonder whether an "aggressive nationalization" type of play could be had now, allowing your civilians to breed CMCs on eligible but undesirable bodies (duranium-only planets, for example) before making them independent, conquering them and moving their installations elsewhere. This has the same energy as building force labor camps for your main race, not something I'd do but something that allows interesting roleplay possibilities.

Also, I can't thank you enough for the ECM changes and the spinal Particles, truly amazing stuff! Something I'd like to ask is whether Sensor Jammers' interaction with ECCM remains unchanged, and whether you've given any thought to the possibility of ECM having partial effects against superior ECCM and vice versa, as discussed here. I know it's not as straightforward as making the ECM penalty multiplicative, but it might be a great addition to the game if done right.

Why not just convert captured CMCs into automines?

A couple of reasons. If they were converted into automated mines, why don't civilians just use auto mines in the first place? Other civilian/commercial equipment tends to be larger and less efficient, so the same should apply to civilian mining colonies. Secondly, for game balance purposes, I didn't want to create an easy source of additional automated mines. The XMC can still be used in the same role, but is less efficient due to the transport requirements.

Yeah, but why not convert them into 10 automines instead of a new facility type? Does taking twice the cargo space really matter?

Ya i see your point you could carry 20 automines to an asteroid for double the production in the same time you bring one XCM. suppose i missed that point.
Still though it would be worth capturing them for the corrundum saving no. you would have to capture 10 automines for the same output. Cargo hauling is never a bottleneck for me in my games so moving it around isnt an issue for me. 

I wonder what problem or gameplay loop Steve was doing to see the need for XCMs

Like the ECM changes.

Why not just convert captured CMCs into automines?

ECMs are 10X more productive then automines. So they would be more sought after.