Anyway, the key to just make sure the plants going from inside lighting to outside are not jumping from shorter to longer dark periods...
This is something i am guilty of...but our long daylight hours make it a feasible technique for me. I run them on 24 hours of light for 45-60 days before planting outdoors(which will be around 15 hours of daily light at that time). Never had an issue in the naturally increasing light regime.(but again this is longer dayight hours than you southern lads) I shouldnt say never....very, very rarely have i had a plant go into an preflower mode....but they keep growing just fine in what i refer to as a "preflower stasis".
Sucha drop, while not 12/12 can be enough to trigger blooming in some strains, genotypes, etc.,...
Remember also my friend, that many strains will trigger well into flower with even more light than 14on/10off. The majority of strains i choose trigger into flower in 14.5 hours of daylight even 15 for some varieties i choose.
Also note, and i think this is the big difference between where he r-grows and I grow, up at that Lat', the rate of light loss is faster than at my Lat',.. we gain/lose about 1 min a day, it's more than that up there; that means while our plants may trigger into bloom close to each other in time, my finishing season is longer than his, to say nothing of the inclement weather...
Yes sir...very different indeed!! Up here we lose 2-3 minutes daily after June 21st(longest day of the year).