Day light is going downwards in august already in my area and august 15th marks the less than 12 Hours day light on calendar. So forcing flower on august 14th for 2 days, once august 16th day light Will be less than 12 hours, like indoor once flowering mode is on.
I don't see how I would miss the stretch as it lasts for weeks and should happen regardless of any force flowering imo. On the contrary, I Hope that plant Will shift full speed in flower rather than sitting there wondering if its veg or flower. Looking at my plants every year I constantly see that plants stall A few days when They switch before showing first signs of flower mode.
But thats theory for now. Have A few months to think about it. I strongly believe that what is done indoor can be applied outdoor, just needs to be tested, fine-tuned & dialed-in.