Sorting the front Suspension

Well a shake down ride today to dial in the new Elka shock and I'm pretty happy how things are going atm, at least until I can sort the front :wall:.

I'm not sure on whether I need to play with the rebound IE heavier oil or the compression (RTGV spring preload).

Bike doesn't bottom hard on big hits, but does use all of the travel (ziptie on fork tube).

my issue is with the smaller stuff (both on and offroad), although it seems to jarr, after I increased the preload it felt firmer but better if that makes sense ?
after hitting an obstacle (tar patches or part exposed rocks) the initial impact doesn't feel to bad, but afterwards feels flat ?
as if the wheel is impacting not rolling over ?

current Set up

(I'm 90ish kg out the shower)
fork brace
0.90 sonics
10wt motorex @ 135mm
6 8mm comp holes
rebound hole as std
yellow spring with 2 turn preload
std top plate

any ideas