I'd suggest that it doesn't really matter - even though there are 9 settings, there is very little (if any) difference between the three groups of three settings, i.e., 1-3 are the roughly the same, 4-6 are the same, and 7-9 are the same.
Just set to soft, medium, or stiff.
Thstone,
Can you adjust compression And rebound on the PSS's..?
I believe the adjustment is for bump (compression) damping only.
I am with topless 4/5 is great for everything. Full soft just does not work well on my car....perhaps it because I have a wider track than most. The car can get way too unsettled on 9... Almost a bit alarming at speed. I might try 1 up front one day to see I can get more turn in feel