Pace, I was aware of the subtle difference between "private flying" and "recreational flying". Very often, there will be little difference. In the present discussion the difference is relevant, however: as a recreational pilot, I positively refuse to count the time for flight preparation, checklists included. The whole flying experience is sufficiently expensive that I won't have any bit of it shaded by time pressure.
When the bill is paid by someone else, that person will wish to have a word to say on how the money is spent - whoever has the money defines the rules of the game, in all games.
Of course we should take care not to obstruct runways, taxiways &C but that is a point of good airmanship & polite manners, nothing to do with the time taken.