I’ve never seen one installed in this manner before.
Looks like a piece of bus designed for grounding which means that it is not being used according to its listing. These typically mount directly to the panel enclosure for EGC connections only.
Maybe that’s how they fixed the double taps from the last inspection?
I doubt the AHJ would find fault.
I would fail it. that’s more dangerous than two grounded conductors under a single lug
But a #10 in a lug with 4/0 is not?
I think you like just being obtuse.
I would fail that too. Neither this nor the OP is a serious hazard.