Our company,
(ADA) stipulate rotor start to rotor stop, after each flight.
BHL once tried mandating Davtron time for both pilot hours and Tech Log entry with the meter set to activate/de-activate at around 29-30% torque on the 212's in Nigeria.
After a couple of months it was found the difference to "normal" flight logging was around 32-34% and questions were then asked more for maintenance reasons than log-book reasons (most didn't care about being 30% short of log book hours, except for the less experienced local pilots).
But there was a fair amount of alarm due to the aircraft possibly overflying important maintenance requirements/servicing by the same amount.
SS.