So i have a pretty big base at the moment and when i want to add assemblers, constructors, etc to the System i often have to check out how much Input i have on a belt, like i can calculate that the Frame Production uses lets say 300 Iron ore. But i cannot see how much Iron Ore is Produced and put on that specific Belt unless i walk aaaall the way to the Miner which sometimes is really far away.
So my suggestion would be to actually see the Input on that specific belt by looking at it or by opening some kind of inventory or specific belt reader building. This would save so much time.