hey fellow simmer
i was also suffering from CTD
at first randomly until the nordic WU, then everything went fine and smooth even with mods.
I was hyped by the SU5 and the promising perf upgrade
yet the update came live constant CTD when pressing fly
did everything to solve the issue trying all the fixes in here
the only thing i didn’t try was to sacrifice a goat on a full moon 
but i finally found a fix (for me at least)
so my msfs is the steam ultra premium edition
eveything was installed on a nvme D drive ( exFat)
Ryzen 5950x
RTX 3090
64gb ram @3200
auto OC on the cpu gpu is stock and i use xmp
what i did :
- format the D drive to NTFS
-reinstall the base game on my main drive (also a nvme) - put back all the package on the D drive
-launched the sim, point the right folder during the install et voilà
i just did 2 short flight to test one of them is bora bora discovery and another one in megève france where i just takeoff
seems to work for now i will give more testing this week-end when i have more time
i don’t know why but it seems ok for now