Have you actually looked at the baseplate on a Holley? The secondary t-slots are not at the same height relative to the baseplate, they sit higher in the bores! Do I have to show you a picture?
The secondary t-slots aren't making much of a contribution since they are not exposed at all until about half-throttle where the progressive linkage starts to open the secondary butterflies! They're just barely cracked at idle.
The intended amount of air/fuel emulsion (not just air) is coming from the squared-up primary t-slots. Due to the high required rpm for a stable idle, more air is required than that primary throttle opening can provide. So it comes from holes as well as some bypass air.
Still a rude schmuck, I see. Go back to your "Fantasy Pro Stock" theories and leave this thread alone. Now added to my short Ignore list. :icon_fU: