You didn't mention the matter of Power Turbine Inlet Temperature (PTIT) as opposed to Jet Pipe Temperature (JPT) or Exhaust Gas Temperature (EGT). Gas velocity isn't as simple as merely looking at the power plant type - it also depends what temperature you're measuring and where. The gas entering the power turbine of a turbo-prop or helicopter power plant may be moving at a much greater velocity and at a much higher temperature than that in the jet-pipe of a jet engine. It may for all practical purposes be indistinguishable from combustion chamber outlet temperature. The Allison engines used in most of the world's C-130 fleet certainly use stagnation type thermocouples to measure PTIT.