aside from many/most of the backside thermal contact pads having anywhere from 25 to 50% of the thermal contact bumps not being there... Make nice jacks for pushing the board away from the sink.
Folks who still have miners unreturned can easily unbolt the heatsinks and verify this. If the bumps were such a problem to make properly then even a thin copper foil shim would have done the trick.
But when mechanicals/thermals are not assembled properly and you just keep putting power on unit after unit that was delivered working, you end up with a huge scrap pile.
No argument there on the scrap factor. Thermal bumps are not final assembly. They are either on the board at time of production or not. And yes continuing to bolt on sinks and burn, er, run the boards when they have such an easily seen by eyeball & felt by finger defect certainly not very smart.