I’ve only done 2 races (actually only one, started a second and then couldn’t be arsed so deleted it) and both times the pace at the front of a Cat D has been unbelievable. Then at the end the top however many who were doing that pace end up at 3.5W/kg and get DQ’ed anyway. So you don’t know who’s really racing and therefore how to race against them, because you don’t know till the end whether they were genuinely in the race or not.
Not that i can see any means of preventing it. And I know weight doping is probably a thing too, but at least with that whether it’s a 100kg man doing 250W average or a 100kg man doing 150W average but pretending he’s only 60kg so he goes faster – at least it’s still the right W/kg so you’re racing against the right band.