I think you are on the right track with adding holes to get some air moving through the doors to get them to open.
I'm thinking your big isn't from too much air and not enough pump shot to cover it, but with double the area of the carbs, I don't think there is enough air flow to get both doors open.
If the doors don't open, you won't get enough air moving through the booster to pull fuel. That's my working theory for now. I resent he right to change my mind like my wife does.
But I think you're on the right track. Can't wait to see how this turns out.