Are you really sure you know about a pt6.
Preformance charts state that you should have max Tq prop rpm wf NG itt within a a limit. As a rule max Tq is achieved at between 96 to 100% NG. This is altitude temp compensated and if you on a b200 a correction factor is also applied.
Whilst the Tq is a oil px reading as I've said. Max Tq oil px is around the 104% mark period. And saying that you can't exceed ITT during over Tq that is the pilot to control. Meaning if you go over max Tq you still are temp limited which means if you get to max itt that dose not mean you can go any further. As yes I no a ****e load about pt6.