On related news, I can now reproduce the traction-based limp mode.
At NJMP Lightning, at the track-out point of the lightbulb where the surface transitions from banked to level, I sometimes lose traction for a fraction of a second. This is at WOT, around 6000rpm and 100-110mph, with all nannies off and yes, an LSD. Right before the shift to 4th. When that happens, I get an immediate limp mode, which leaves no error codes stored on the computer.
Pit in, restart car, and pit out. Without codes stored, not sure how to troubleshoot this further.