Don,
Time for some leave ay mate?
I never suggested that they turn of the engines. I said that PLANNING on canberra is a fair weather option. If the weather turnes against you then you have to divert to Canberra. What you DONT do is then depart Canberra when by doing so you exceed Max FDP.
Notams suggest a minimum of 20mins fuel for holding a peak periods but as I said commerciality is forcing flight safety into the shadows.
Now sit down have a beer and plan your next vacation my old friend