530D low revs power loss and higher fuel consumption

[toml812]

Hi, for starters, sorry for my english. I also tried to search the forum here and internet, but hasn't found anything I haven't tried or made similar case with my issue.
I got E61 LCI (2009), 173KW/235PS, M57N2 engine. Swirl flaps, EGR, DPF all present and working fine, according the my trusted indie tech. I also have ISTA-D and can do some very basic checks myself.

I bought the car in May this year and previously I had E61 preLCI for 8 years so kind of have experience with this car and can tell something is wrong with the new one.
first when I bought the car I heard weird noise from turbo, and except that there was 2 seconds lag until the car downshifted and it started accelerating. it turned out turbo is really bad and also the boost actuator wasn't working alright. I replaced it for re-manufactured turbo. immediatelly improvement, the car started to be more predictable, same as the old one.
but I still experience some low revs low power. my indie tech is out of ideas what that might be as everything looks alright.
air-mass system test passed, boost pressure actuator test passed alright, system was verified for air leak, dpf backpressure is fine, almost like on the new car, egr actuator working fine...

the point is I need to press the accelerator pedal on this LCI car further so the car actually accelerate and it's not subjective feeling. the preLCI was accelerating smoothly from about 1200 rpm, this isn't. it's going up slower and only kicks in from about 1800 rpm, what is actually start of zone of max torque and where the turbo starts to work 100%.
driving the same pattern as I did with my previous car also resulted in increased fuel consumption. even driving on the high way using cruise control gives 1l/100km higher consumption so it's not about heavy foot. but when I'd want to drive with same dynamics as the old car, it would be even worse.
as I can't give here full list of the performed actions and tests I understand you might say good diagnostics is the bacics, but full diagnostics were done and what I suspect is that we're overlooking something, therefore my question is what might be causing low revs power loss and higher fuel consumption? I'd be glad for any advice.