I still doesn't know how to capture immovables. "green connection" - how to get that?
The only structures you can capture in this build is the scattered crates, all other structures that say you can capture them are a bug. Capturing crates only allows you to "salvage" them for supplies.
The green connections is what you see displayed on a grid when you are building corridors, it represents the parts of your base that crew can walk through- some buildings need to connect to this, and others dont.