@bburkley I have been having a terrible time with my rig/msfs not playing ball but I seem to have got to the bottom of it all (touch wood). A lot of folks are complaining of stuttering since SU9 and CTD issues etc. I did lots of things so they all could have had an effect but the thing that stopped the crashes and stutters ultimately was to switch the task priority of msfs to Low via task manager and to prioritize Background services instead of Programs in advanced system settings.
Have a read at this and give it a bash if you haven't already: https://www.reddit.com/r/flightsim/comments/idmdqq/update_msfs_2020_stuttering_when_window_focused/
There is every chance it is entirely unrelated but every little helps!