I fully understand one does not need this huge production capability, in fact and in another savegame erverything works fine in a small manner, like in yours. But what do you do when you have everything automated (Radio Control Units, Turbomotors, Nobeliks...) and the game just can not give you more at this stage of development. As it comes to me I started over and am now going for the huge production lines and to get the game to the edge.
In fact it is a lot more satisfying, at least for me, when I hit the borders of this game because in a reverse assumption it is obvious the game does not need those huge lines to fulfill the target in the end like you stated :-)
Though...it is a bummer nevertheless and this is the reason why I asked how do you troubleshoot this when having serveral hundred hours of gameplay and fool around with the game like me.