It's an intended mechanic that the transmission efficiency of beacons has diminishing returns when multiple beacons affect a machine. However, these diminishing returns are applied even when a beacon is empty.
Steps to reproduce:
 - Place an assembly machine. Hover over to see its "Crafting speed"
 - Add an adjacent beacon, with speed modules inside. Observe that the "Crafting speed" increases.
 - Add an adjacent beacon, this one empty. Observe that the "Crafting speed" decreases.
Observed behaviour:
 - The addition of an empty beacon reduces the effect of the filled beacon.
Expected behaviour:
 - The empty beacon should have no impact on the transmission efficiency of the filled beacon.
 - (Sensible extension to the above:) If a beacon has 1 of 2 module slots filled, then its diminishment of the transmission efficiency of other beacons should be halved. E.g. it should be considered 'half a beacon' for the purpose of calculations.
Gameplay effect of this bug:
 - It is not possible to dynamically change the modules in beacons (e.g. pulling out productivity modules when input resources are in surplus) without incurring a transmission efficiency penalty to other nearby beacons.
 - It just doesn't make sense really. It's counterintuitive and I see no balance reason for it.
			
			
									
									
						
