To paraphrase FSI, "whenever the prop RPM is below the selected RPM you are on the Low Pitch Stop"
On the -67
Flight range PCU controls prop RPM, Power Levers/FCU controls engine N1 combination of the 2 gives your power
Beta Range Cam on power lever controls prop pitch, engine runs at idle
Beta Reverse Range Cam controls both blade angle, and N1 RPM
More complicated than that I know, but in flight it is just that simple. There is a WoW switch preventing ground idle/LoPitch Stop, but lifting the levers bypasses this, and yes it does make for a sudden arrival. "nothing damaged but my pride"