Maximum Density Smelting. [proof of concept] UPDATE!
Now with examples! Using every trick in my book & more I came up with this small array. Uses off grid belt dots to move sorter input angle enough to fit 4 sorters + the occasional power station. All within 1 tile wide gap. Then teleports the outputs/inputs to/from a belt above. The belt is half offset the grid to avoid the power pole. The final, smallest one is so small, it cannot fit power within itself. that means any larger setups would need to add gaps to create power. a simple example would be replacing a single smelter with a satellite substation.
Paste in creative mode to test.
If anything isn't running at full speed, fiddle with the timings of the balancer/splitter by letting things back up. All the important ones should work fine.