Jim Carriere wrote

Of course Ron, you're right, the .1 or .2 between startup and taking the
runway technically aren't supposed to be logged.

If you're taxiing out in order to intentionally fly it
sure is loggable as flight time. I posted the FAA's
definition of flight time elsewhere in the thread.

As for how to measure logged time, I don't have a
Hobbs or a reliable recording tach in the cockpit.
I use 'wris****ch' time.

Dave 'not P-51 time' Hyde