I don’t know if this is intentional or not but you can’t put the generator back into the rover once you unload it at Laurion, haven’t tested it at other facilities
It's not exactly intentional, but it is expected. The only reason to unload the generator is to load something else instead, so I never really expected players to change their mind and want to load it back on again.
That being said, recent improvements have made it much easier for me to add actions like this. Previously, I'd have to make a Load and and Unload action for each location you can unload it at. Now I can just make one action, and it'll use that same action for every location. So I will be adding this soon. Possibly not next update, since it'll be out very soon, but definitely the one after.