I dont see much of problem in that log ..
the boost pressure follows the request = good
Only what i'd do is try to smooth a 3,2k-3,6k part in request.
These maps have an effect on the final boost request what you see in logs:
KFMIRL
LDRXN(ZK)
KFLDHBN
that could be evened out just with the help of those, with a small changes...I'd just go straight to LDRXN and KFLDHBN first and look what numbers they contain...
Up from 3600rpm everything looks decent for K03S? turbo, it should taper down after 4k, thats not a fault. You can put more request (raise KFLDHBN+LDRXN if needed) and turn your turbo into a real heat pump but that's hardly desired?
I can't offer anything else since I'm a beginner myself, it's worth reading a few times
https://s4wiki.com/wiki/Tuning#Specifying_requested_boost