Okay - for some reason, I can’t build a vehicle forge rig; the electric forge component shows up in red in the crafting menu even though I’m holding it in my inventory. I decided to circumvent this by just adding a UPS conversion mod on to the forge.
Pros: the UPS-modded forge now shows up in green in the crafting menu.
Cons: The act of applying the UPS mod had spawned a none. It crashed the game when I tried picking it up and then dropping it.
Someone should take a look into this issue.