Dual quads versus big hammer!!!...

I see..... like where they point out:

Air Valve - These secondaries have an air valve, similar to a choke blade, above the barrels. As carburetor vacuum increases, it opens the air valve.

Like as I mentioned previously...... air flow on demand.

The root cause of the doors not opening at wot and low rpms is very simple.
The motor doesn’t need 1250cfm of carb capacity at 2000rpm.
The two primary sections are apparently enough to keep up with the air flow demand of that motor during those conditions.

I’m not saying modifying something to trick the doors into opening sooner won’t help the situation...... you’re just covering up a shortfall of that carb design for that particular application.