Back in August, I used process lasso in win10 to manage the affinity for running processes in all sims. Even in p3d addons it worked fine with everything except concorde. concorde kept overriding the affinity mask. If I set the process lasso to constantly monitor and enforce my affinity settings, concorde did the same, they fought each other, the affinity mask kept changing.
The renderasync setting you found improves performance significantly for me as well.