Rift S settings discussion

My spec
I9-9700k
32gb
GTX 1080
Rift S

I think I’ve spent as much time tweaking as flying to get a smooth performance, however whenever I start the SIM on a different day I get the stuttering back again, it’s so frustrating.
After so many adjustments I think I have found the sweet spot.
Render scale - 70
LOD - 90

OTT
SS - 1.7
ASW - 18