I don't know how possible this would be, but having the ability to alter individual belt box stacking would be Huge for belt movement. For instance, if I want to bring lines into a mall, but need 10 belts of Iron to fill everything, even compressed that is 2 compressed Iron Plates. But if I could set the Iron Plate Compression belts to 20, then I would only need 1/2 lane of Iron compressed to fill the same needs. Extrapolate this out and the flexibility of this would be great, especially as mods make the game more complex and resource types increase many many times, creating an already packed system of belts without needing also multiples of each line.

Would it be possible to do? I assume the problem here would be on the unpacking side as the loaders would have to either also be set properly, or be able to just "unpack" anything that comes in. (Would think the first would be easier since if it was set improperly it could just act like a recipe without the proper input.)