It'd be great if SE things could be used in the lab. To help figure it out, here is the list of SE things I found to not work in the lab:
- Space-only tiles (Scaffold and Plating). Lab doesn't qualify as a space surface.
- Space-only machines. Same as above.
- Cargo Rocket Silos and Landing Pad. While those are not space-only, SE is probably checking if they are placed either in space or on a planet/moon surface. Probably to exclude rocket stuff from being placed on spaceship surfaces.
I have yet to unlock spaceships in my game but I would guess that a bunch of stuff used to make them wouldn't work in the lab either.