We had good "lift" conditions up here last Sunday on VHF running NW-SE and I did notice some increase in range on Radarbox.
However, I'm never quite sure just how much a tropo opening will affect this system given the altitude of these aircraft. I've been in situations with V/UHF where you can be above a duct when operating from a hilltop site at a few hundred metres - esp if there is a sea water path involved.