Anyone have a quick way of clearing all variants previously set upstream. Setting them all to (<block>). the asterix * in variant set slot won't do it. If not, then a python LOP might be the answer. But not sure how to retrieve the variant set names. Anyone tried?

There is a For Each LOP mode to iterate over all variant sets on a prim.

mtucker
There is a For Each LOP mode to iterate over all variant sets on a prim.

Holy crap! How have I've not seen that mode before? You just made my day!