Boss mustang tune hanging idle

Hey guys, we recently did a tune on a 2014 boss mustang, which worked well on both ends of the tune (track key as well as black key) customer is really happy with the track key, however he complains of a dashpot / hanging idle on the black key. The red key from the factory is set up for full engine braking and has next to no dashpot from the get go. The only areas of the tune that were really changed were the higher load/rpm spark and fuel tables..... when i load the original read back into the car, the idle problem doesnt exist. I have not made ANY changes to the dashpot, idle, or anything maf related down there that could cause this.... I even went to the extent of building a file based on only changing track key related things, and left the black key completely stock, and it still does it. I personally tried driving it, and my customer is correct, it hangs. The only time it does not hang between gears and want to drive itself when it is, is if i put the original read back in it? i have included both original read and my version of the tune in this. Using 3.6.26 version..... Any ideas? thanks Nick