After using PacePro for several times I can now say with a high degree of certainty that even if I use a FP for my running pace, the PacePro screen is not using it and rely only of GPS pace. If this may work relatively well on flat with clear sky visibility, in trail conditions under trees, relying on GPS pace is a bad decision.
Ideally the user could decide which pace to use, or, if this is not possible, I would prefer by far FP pace in any condition.
Maybe Garmin is listening to these posts and does something about it.