I myself use a Herbies Grungebuster Washer that he specifically makes for the VPI Spindle.
With Harry's design, the whole affair was designed to work together. The circular depression in the Platter, the Washer, and the cupped face of the underside of Clamp.
But one cannot just blindly clamp the bejesus out of a record, thinking if a little is good, then more is better.
Over-clamping will actually make the record's edge again lift away from the Platter.
The variance of clamping pressure then allows one to best couple the record on a record to record basis. That you have to observe the record's edge while clamping as it begins to make contact with the outer edge, and perimeter of the Platter.
Yes, there's perhaps going to be the occasional instance of where slight warps, or funny dishing-cupping of the record will not permit this design to work optimally.
Probably one reason Harry then came along with the Periphery Ring for later model Turntables.
With Clamps-Weights such as the TTWeights designs, I understand these are not to be used with the Spindle Washer.