It's probably not pre-turbo temp. Usually IAT is measured near the throttle body but since the Intercooler is in the manifold, it could be before or after cooling. idk
Unfortunately, if the dealer does a teardown, they aren't likely to find a problem. They'll probably only see the results of slipping (ie. hot spots).
I sense that you have prior experience with manual transmissions. Enough so that you can tell the difference between defect and out right abuse...
This was true for the first 3 years of ownership but most of the 2020 MY Supras are needing to start OBD testing which checks to see if the emissions component tests (readiness) have run and passed.
Question for anybody with a tuned supra - does your car pass emissions testing here in NC? I'm specifically on MHD with a downpipe.
I know we can have one readiness monitor "Not Ready" and still be ok.
Let me know what your experience has been.
This is what my readiness looks like:
I'm up there the 2nd week of April with VW and would be down for an encore with the Supra. We usually organize around Fontana Village, but the past few years we've done AirBNB's near by.