I'd assume you lowered the shift rpm and shift mph in sport mode because of the Nitrous? your normal mode shift higher at WOT compared to sport ?
I tried something like that and it didn't work, i tried more pressure, didn't work, i tried more TM, didn't work, i tried changing the shift mph and lowering the rpm so the shift was more mph based rather than rpm,(in theory) and it didn't work, i tried making the shifts times slower, it didn't work.
Try this, put back the tip-in tq mgmt/upshift, flare tq mgmt/upshift and torque reduction/speed ctrl termination back to stock. i don't think the first one have anything to do with the issue since it happens at WOT only, and at the track, but i'm not touching that one until i can double check the 3-4 WOT shift at the track at least a couple of times
On my last track visit, i had 8 runs, and the only thing i changed was this 3 settings in desperation, and after that, got two more runs for a total of 10 passes. This last 2 runs were 100% clean.
July 17 is my next track visit so i'll be able to double check and confirm.