Last Sunday I did a 5 mile run on the 1/4 mile 'paved' high school track because it was right next to the 100 meter swimming pool that I was going to swim 2K in. The run and the swim went fine. However the next day I did experience a minor flare-up in PF !
I have to conclude that the rubberized pavement on the track was much more demanding on my feet than the dirt/gravel trails that I am used to. So: 'Pavement Matters' !
Another observation, I am convinced that my weekly 150 miles of biking and 5 miles of swimming have helped heal my PF. Feet and legs always start to feel better during a distance swim.
I hope this helps someone.