I'm so glad we are on the same page here....
regarding this "difference in brightness between push and pull"
i can tell you that is classic Bruti bullshit, ...
with roland it was the supernatural reed flatulence, notes actually
sounding flat as the "reed" first starts to move, and the exaggerated
key noise etc. that was actually amplified into the waveforms to
a level it could be "pointed out" in a demonstration
We don't need any of that "flaw bullshit" in a digital accordion.
To me some of the great advantages of the digital accordion are 1) no volume difference between individual notes, caused by small differences in voicing, 2) no volume and timbre differences between the different reed blocks in cassotto (especially noticeable with accordions that have three reed blocks in cassotto), 3) no notes where some reeds start faster/slower than the other reeds (like H starting before L), 4) no excessive drop in frequency with low notes on push, 5) no loud noise on key press and key release due to aging of the felt, 6) no valve noise with either leather or plastic valves and 7) no reeds starting higher and then sagging down to the stable frequency, as I observed in older accordions of different brands and with reeds from different manufacturers (probably due to metal fatigue), 8) no rattling sound from the bass mechanism... I can keep going here...
What we need is great accordion sound without any of these flaws, just like I get great grand piano sound from my Yamaha digital piano without the hammer felt wearing out, the strings going out of tune, etc. If they focused their attention at Korg to creating that great accordion sound the Fisa Supreme would certainly sound still better than it does in the first demos (although it's already better than the Roland FR8x and FR4x).