I see a problem here: unlike conveyor lifts, neither building ports nor splitters/mergers have set transfer speed. Assuming you have three Mk5 belts carrying some resource, you merge them with a merger, attach a splitter to its output and draw three Mk5 belts out of its outputs, how fast should it process these carried resources?
Assuming the speed of that connection is infinite, it could be used to solve the "problem" that fully overclocked Mk3 miner provides resources faster than a Mk5 belt can carry - just stick a splitter to its output and use multiple belts. But since you can merge essentially anything to such single output as per previous example, the question is how much of it can you do before you crash the game.
