You really don't want trans fluid over 90 at all. Its best to keep it at 80 and under, it deteriorates extremely quickly over those temps. I have a bypass and separate cooler with fan and mine never gets over 80. Also, I know it sucks on the track but if you haven't got a fully built ZF you should just leave it in sports mode and not change gears manually. From what I've heard most failures are with sticky tyres and manual gear changes.
This is just off the web, but I have heard it a few times and when I had the factory set up the transmission was just slop after 90.
http://thetransmissioncentre.com.au/?page_id=105#:~:text=Normal driving will raise fluid,say up to 160%2C000 km.