i've chased the gremlins that live between "idle" and "Wide-Open" in a few carb models during years of off-roading. We experimented with different accelerator pumps/linkage adjustment, fuel bowl levels, inlet PSI, idle mixer and jet sizes, bla bla bla...... all in search of the smooth controlled off-idle transition performance.
we finially figured it out "fuel injection".

anyway, i just want all 3 carbs.

but i just can't get it through my head why running of the center chocked carb alone, and then somewhere past off-idle the other 2 carbs via "progressive linkage" kick in, would be so hard to tune?

sorry for being so off post topic, just enjoying the dicussion