There are several of us that run temp stickers on our calipers. With track pads that lack thermal shims, caliper temps are upwards of 450°F, enough to boil every DOT4 except one.
Dry boiling point is a nearly useless measurement. In reality, as soon as you open the container, it'll no longer be at the dry boiling point and will work its way to the wet boiling point. The specification you should be looking at is the wet boiling point.
Castrol SRF is the benchmark for doing it right for track prep. Everything else is a compromise. Motul 660 is a marketing trick; their RBF600 is a better fluid with a higher wet boiling point for less money.
1 liter of ATE Typ 200 is $17 w/ 396F WBP
1 liter of Motul RBF600 is $37 w/ 421F WBP
1 liter of Motul RBF660 is $58 w/ 401 WBP, a bad value given it's only a few degrees better than Typ 200 for over 3x the price.
1 liter of Castrol SRF is $70 w/ 521 WBP
Pegasus has a handy chart that shows the usual suspects:
https://www.pegasusautoracing.com/gr...pID=BRAKEFLUID