2014 Silverado L83 A6 with a single S366
From what I understand, the only thing the DD table does is convert a pedal position to a torque request, and that is it. You would think that the high values in the DD need to be larger than what the engine can produce to command 100%, but I don't think it is that simple.
What I think happens is: the pedal sends a torque request to the computer, the computer maps the request against the VTT to determine a desired MAP and Airmass (spark and cam angle are controlled by RPM), if the VTT are not 100% correct, which I don't think they can be, then you will get a desired MAP and Airmass that results in a produced torque that is higher or lower than the commanded torque from the DD. To correct for this, I think the computer also estimates produced torque using the MAF and corrects for the VTT error to some degree. That is where fudge factor comes into play between the DD request and what the engines produces.
You seem to be doing the right thing with your minor adjustments to the DD table for driving feel preference, and in general the top of the DD should be larger than the most power you want to make.
I don't think the DD does anything with the trans. The trans seems to look at delivered torque, immediate torque,and predicted torque when it goes into a shift. If they are all not in a nice line then it does some wacky things with TM to try and fix things, which is causing the shifting problems that I am having.
I have not found the equation for MaxTrq listed anywhere either, it would be nice if TriPinTaZ can provide a link.