That's the long way to say you do it by the book Ian But there's no way I'm taking the head off every time I do the timing, especially on my ES2 or Manx
the last time i adjusted the ignition on my M20 i secured the timing in the middle of the lever on the handle bar, with 2 dots to find the right timing back again, after starting the bike.
I know its is not very accurate, but this timing never is with the tension on the cable and so on.
This allows me to easely change the timing in case the timing slowly changes over the years.