![Smile :)](./images/smilies/icon_e_smile.gif)
So, the belt can carry two lines of goods, but there is no easy way to combine them, and also no way at all to split them. So how about this (see attach 1): the splitter that splits two lines of the input belt into two separate outputs.
Likewise, it would be nice to be able to merge lines (see attach 2): a 1-by-1 device that will put the bottom line up or top line down, depending on the setup.