Just kidding. But I would appreciate knowing how the percentage of dust created is apportioned differently top and bottom with a zero clearance insert installed in a table saw.

As I am building this cabinet to contain an old contractor saw I anticipate that there will be less dust that gets into the bottom of the cabinet. So I am anticipating that the real action is in the dust collection at the blade. I picked up a used Biesemeyer T-Square Blade Guard and am contemplating how to increase the size of the dust port.

But my real question is about the difference in need for collection below the table when using a zero clearance insert versus the big bags of sawdust below the saw cabinet I am used to with the factory insert. I imagine that there is the requirement for some dust control but am wondering if 6" of port diameter out the bottom connecting to the main run which is 6" is overkill at the same time that I am worrying that less than 4" (I forget the actual size of the Biesemeyer dust port at the blade guard) is sufficient.

What difference does a zero clearance insert make below the table and what is the consensus on what it take to clear it to the central mains which are 6"?