I get the same results using the stock CFG in P3D 2.0 or adding [JOBSCHEDULER] AffinityMask=14 setting. About 35-40% CPU usage max and 46 threads on an I7-3770K OCd to 4.3Ghz.
However, when I set [JOBSCHEDULER] AffinityMask=15, I get worse performance - 20% reduction in FPS, the same amount of threads, and 50% CPU usage.
For me, leaving at stock for now works the best, but it seems like there is a lot of room for improvement of cores/thread usage in P3D that is waiting to be tapped.