The spring's free length is 250 mm. You should be able to get the sags close with less than 10 mm preload on the spring, ie no more than 240 mm long on the shock. Try for 30 mm static and 100 mm laden
Back off the high speed compression first, the outer adjuster on the shock reservoir. Speed relates to the speed of shaft travel and for compliance over rocky ground we want it to move quickly, they are too stiff standard.
Steve