Picher, if pressure points can reduce amplitude of barrel vibrations, causing different bullet weights and loads to shoot closer to the same POI, that's interesting. I've never heard of this before.
If one were to hold a ruler down on the edge of a table with about 9 inches hanging over and stroked the ruler, it will vibrate with greater amplitude and lower frequency than if only about 6 inches hangs over. The sound will also be in a lower key.
Therefore, a barrel will vibrate with less vertical amplitude (but higher frequency) if there is a pressure point with adequate force within the barrel channel. Since the greater barrel vibration amplitude is in the vertical, doesn't it make sense that vertical dispersion will be less when shooting different bullet weights and velocities?
Longitudinal position of the pressure pad within the barrel channel is also a factor in tuning a rifle for best groups.
Again, I still think barrels should be free-floated for most consistency of POI and rest options. Single screw actions are the most common instance for my use of pressure pads, but an older CZ Varmint shot better with one, after eliminating the barrel stud screw.