Here is the science behind typical tunnel rams operating better with a direct rather than a progressive linkage, down in the tunnel ram section. Intake Manifold Comments
I only read a little of that link you posted. When I find at least 2 errors in the first two sections I punt.
There is ZERO reason for a TR to have throttle response better than anything else (it should) and it should idle better than anything else and posting the same carb CFM selection math is just dumb. That formula was wrong when it was written, and it's wrong now. Nothing has changed.