As I commented elsewhere, this seems to be over-simplifying. The addPartitioningExpression was originally just collecting a sample "token" partitioning column on an actual table, now it seems like you are trying to build something more significant on it, but I don't think that it holds up under the pressure.

I hope that it will turn out to be simpler to (mostly) ignore the result of addPartitioningExpression and concentrate on the valueEquivalenceSets.