Stacking items on belts for increased throughput

[Cellfire]

Maybe items on belts could stack after you do some research for it. This can increase throughput of each belt type and reduce the number of belts lanes need for large setups.

Current 1 iron plate or product image on a belt is 1 iron plate or product. If the image contained 2 iron plates or products, right away you can half the number of belts you need or double a production line.

For visual side of it maybe the iron plate or product image could even be a box with the icon of the iron plate or product.

This may help to keep belts an option far into the late game without some silly 32 lane iron smelter.

Hope you understand what I mean.