I use that combo myself on occasion and it works very nicely--certainly improves the VdH, IMO. Consider tossing a drip or two of glycerin if you have any on hand, to see how you like the uberlather.
KMF Patchouli right out of the pump and into my lathering bowl, with a few swirls of my brush BAMMMM.....good lather and plenty of it! Maybe better than good, but not great and there's nothing wrong with that!
Which VDH soap? Luxury or Deluxe? I too make super/uberlathers with VDH and KMF, but have been using Arko a lot more recently. I bought a big pack of both Arko and VDH at the same time. And now I've got a few other soaps...I don't think i'll run out any time soon...Oh man, I think I have SSAD (Shaving Soap AD).