We find when scanning a C6 with a Ease PCM scanner some changes in how GM does things.

One thing we are trying to find out is that we notice where the C5 had 23 fuel trim cells that the C6 has at least 38 cells. We have to find out what each cell does for GM re-mapped all the cells so even cells that were known for a certain engine condition have also changed.

Also we see the new function GM has for protecting drivetrain on launching.
The following scanner data clearly shows what happens when a hard launch is done.

Look at RPMs, TPS, load, misfires, etc and then look at injector pulse width (PWB2) and you see that when PCM sees hard launch it does not command injector ON time yet engine load, MAP, etc increase thus causes false misfire counts.
Also notice the elpased time and then the elapsed distance values and you see how the launch control cost in getting the car rolling.

This is confirmed in using LS2edit we see new launch parameters where PCM can control drivetrain protection by reducing fuel,timing or closing the butterfly of TB via ETC.

Can you lower the speed in the launch control box, to make the mph lower or could you toggle off the reduced throttle and fuel trims with LS2 edit. That might solve some of the launch problems you have found.

The setting your talking about only is the trigger when launch control works so if you changed the stock setting which you see at 317 MPH to lets say 5 MPH then it would work from 0 to 5 MPH and not above that and as you see the car is at zero MPH at launch so lowering the value would not help.

Either GM did not also include a table with multi values to tweak this condition or LS2edit has not found those tables.