I understand. There is always a gameplay balance issue to maintain as well as ROI in programming effort. Your current campaign just seems to highlight a pretty large gap in strategy gaming logic.
It just seems illogical to me that something so monumental as building a 10000+ ton spacecraft can occur with an enemy staring at the assembly line and everyone just goes on about their business; having their management meetings, drinking a cup of coffee, maybe checking the Aurora forums instead of doing their reports? 
He has the option of shooting at the shipyards. He's choosen not to exercise that option.
If he could park ships in orbit he could also yoink the shipyards with a tug.
I don't see the problem. Additional options might be nice, but Aurora's got it's bases covered here.
Besides, boarding actions opens a bit of a potential can of worms; shipyards employ millions of people on the planet, there's certainly going to be alot of surface to space traffic, and transport capacity. So why couldn't a shipyard in orbit be defended - or attacked by - ground troops from the surface? And if so, how would that work? Yes, yes, 'if you control the orbitals you can (try to) shoot down any shuttles ferrying troops up'(maybe expose the troops to hostile point-defence fire for a short time?), but what if the boarder can't hold the orbitals? You could end up with an awkward situation where the enemy captured your shipyards before reinforcments drove them off, and if you don't have any surviving troop ships, you.. what? Have to build a whole new shipyard to build a troopship to board your own shipyard in orbit of your homeworld?
