Generator gas overflow even after changing regulator

Sounds like a leak past the CARB NEEDLE AND SEAT.

Could high fuel pressure be a contributing factor? Sure.

But can't imagine how it could run smoothly with fuel mixture that far out (raw gas pouring into the intake and air cleaner).

Were this a mechanical fuel pump where the "back side" of the pump is lubed by engine oil, that would be another pathway, but not with an electric fuel pump.