FINISHED THE ADVENTURE AFTER 57 SESSIONS!
It took two years and three months playing mostly every other week.
One unusual thing about my run is that we used strict XP advancement instead of milestone leveling. I had to get creative with adding extra material and using almost all the encounters from both the Path of Demons and the Path of Devils.
If anyone has any questions for a person who's run the whole thing, I'm available! Meanwhile, I'm thrilled to be done.