I come from working in FCP and have only recently made the switch to Premiere. I am working in 5.5.2 on an intel based iMac, and the highlight tonal range definition function inside the 3-way color corrector is not working. Shadow definition works splenidly, but the softness setting for the highlighs does absolutly nothing. I can control the threshold, and that's it. Thanks in advance.
I have a CC and grade session later this morning.
I will check your issue on my Windows system and report back.