No one knows more about this stuff than you. But I don't understand what you're saying here. Let's say that you're right and you can break more successfully with a gap. Do other players know or believe that? If they look at the rack and their opponent gave them a gap or two, they won't complain about it? I simply don't believe it. They'll have their own ideas about what they want, right or wrong. And if they rack their own they'll get what they want, but if their opponent racks they won't like it. 
It's not even about what rack is truly best, it's about whether the player perceives their fate to be in their own hands or their opponent's. Guess which they'll prefer.
But I'd be happy to be proven wrong about this. Let opponents rack, watch the sh!t show that will inevitably ensue, and let it be the death of opponent racks. :wink: