UI: Efficiency View: Filter by "starved" / "smothered"

There are two reasons why a machine looses efficiency:
1. It does not get enough inputs (lets call this "starved")
2. It cannot output because the belt is full (lets call this "smothered")

It'd be nice if an upgraded efficiency view could be toggled to only consider efficiency loss from either source. I for example build lots of setups with smothered machines so often only care about starvation.