Yeah, APUG does not like formatted data! Bummer.
Ok, you do not have to have the best developer to get a benchmark on the properties of developer ingredients. So, this particular developer series might well be worse than D76. And, if the developer is too far out of line, it can reorder results of all films. I've seen that where a coating passed all specs and I ran it through other developers the coating failed in several parameters while giving the accepted curve shape and speed.
So, I cannot comment on what they got, but I'll bet that the reasons and a lot more facts were explained in internal reports!
The sharpness tests plotted as response vs spatial frequency and is MTF (Modulation Transfer Function). These tests include all edge effects and that means bad or good.