Very part intensive and setup heavy but extremely uniform bus system that even allows for outputs. High demand items should be routed on the bottom first and with decreasing demand first closer to the machine and then up. That will save on splitters because when a machine doesn't need that item there is no splitter required on that level in that position and the belt can just be passed along. For an output a splitter is needed on a level and position that is not or no longer used as an input. The nature of the bus becomes 3 dimensional and is very labour intensive to build and set up. Each box on its level which acts as an input needs to have its filter set only on that level for that item type. Filters cannot be copied to each box. It is very part intensive and not really suitable for early game because of the low blueprint part count. A much higher number of sorters and belts are required. That is the downside. The benefit however is a massive space saving. It can effectively build every item in the game. At level 3 vertical construction boxes can be 5 high which means it can support 15 ! lanes of belts. Yellow science depot height can go up to 7 which means 21 ! lanes of belts. That can then easily include 4 inputs of machines and the output to feed into other assemblers making it possible to construct everything, even the new items and the ammo with careful planning and phasing out no longer needed belts for items further down the line to craft the more specialized buildings. However that is a gigantic task and will require all the research for stack height which I don't currently have in my dark fog save, because there are new recipes that require dark fog drops such as a new fuelrod and a new 3x speed assembler and matrix lab. Not to mention this method also adds an automatic drone port to the input list for every assembler automatically.