Hey, "Remote Play Together" has been brought to my attention by two different guys. And it seems to be just a toggle I enable on Steam for VA. So. There you go. Enjoy!
For those that don't know, RPT lets you stream your game to a friend and "share your keyboard". Your PC take's your friend's control inputs as well as yours. I can't guarantee that it will be a lagless experience - that's not something I control - but the option is now there for cooperative ship building with a friend if you want.