i noticed on one of your dyno graphs that when your engine was near its peak power figure that the curve went flat for quite a while...

i have a b20vtec with quads and it did the same ...when it got close to its peak power the curve went flat and did not drop off for quite a bit longer thean yours..
It had great mid range but i would lose that if i tried to move the peak power up in the rev range to try and get rid of it flat lining

I thought it was starving of air ....thought it was the exhaust tried every thing.... never could work it out
Eventurly took off the quads and super charged it
Torque to burn and it still fells like it NA