RHD,
You are still missing the point. And that point was quite clear in the H book & numerous others about how the AB size controls the start of the fuel fuel. How much fuel flows after that is another story. I don't have any argument with the rest of your comment.
The simple fact is that there IS air mixed with the fuel when the MAB size allows the start up of the main system. It is NOT solid fuel.
I suggest you buy John Passini's Weber book, ISBN 9781855207592. He has forgotten more than the rest will ever know. Go to p.32. Where he says this [ in part ]:
'With a further increase in gas speed through the venturi, the depression caused will begin to lift fuel in the well....'