I believe you're referring to the restriction of placing normal belt in space/ships, and placing normal machines (like Electric Furnace, Assembling Machines, Chemical Plant, etc) in space/ships; is that correct?
My initial thoughts are like yours, it's such a pain to have to build different buildings, just because it's in space. Especially when we probably already have a mall on Nauvis producing all those machines. However, a significant part of SE is balanced and built around the different machines and belts that exist for space. And, although it is difficult, that is part of what makes SE attractive. It provides a new challenge, and requires players to change their standard play style in order to succeed.
I'm probably not going to add something like this in, but I'm not totally set on it, and could be convinced by a good argument. I don't think "SE is too hard" is a good argument, unfortunately; that is what Earendel's goal is: to make a hard mod-pack that challenges players again.
As a side note, SE 0.7 introduces a toolbar button, that you can click with a blueprint (or book) and it converts normal Nauvis belts into space belt, and converts Nauvis rail into space rail. My first playthrough, that was my hardest problem: converting all my balancer/rail blueprints to space. Perhaps that will help ease the troubles of adjusting to SE's space features.
