I just asked this exact question on the foundry mod. Then I come to this mod and find this post. So forgive my "double posting".
I'm curious if you could add a startup option to each of the mods that adds back the recipe for building they are integrating make itself as they do in Space Age. You already have start options to let the EM and foundry make some of the space only recipes so why not add this one too. I don't care if they can or can not make other production buildings I just want them to be able to make themselves again.