Increasing time of light cycle seemed to speed them up some. Considerably better than 12/12 or 18/6. I noticed 24/0 worked well on straight grows. LST to your heart's desire,,, just don't cut anything (like topping / FIMing) and she'll grow fast.
... and push the nutes a bit too for the longer cycle. They'll appreciate it.
I did notice that with autos it all depend on the environment as for run time.
Like EGrower said," speeds up by 2 weeks". I'll agree to that.. perhaps even more if you want clear tricks (not always a bad thing"). But we disagree about bloom boosters & flower feeds.
I'm Northeast too. New England. Don't down play the value of a Autoflower. They have their place. Only reason I no longer run them is because I like to clone, make fem seeds, cross breed, etc. I also set up grows for card holding handicaps & old veterans. Auto will give you a speed lesson on growing... sometimes the hard way, but fast. Don't be concerned with N.E. "high temps",,, Google up some info on heat indexing and plants. Cross ref to a RH grow index. You'll see that temp and humidity work together and it's a tool you can use for heat & cold conditions.
Last year we got hit with Hurricane Sandy & blizzard Hugo. Lost power for 3 & 4 days. Temps went to 46F without any light, circulation, nothing. Each time they came right back and back on track with time. Also in the summer, by working the R.H. I was running 91 to 94F with out CO2. They survived just fine. Only difference was... the friggin trich were one on top of the other! Damned near pure white where facing the bulb.
Don't be shy with them autos. They've come a long ways the past few years. The quality is every bit as good as most any photo, AND THEY ARE NOT LIGHT SENSITIVE! That's a huge plus. I rarely closed the grow. Kept them "happy" and the only time they'd smell was if something was wrong. Fix & smell gone. I will say,,, it'll make a "Plant Reader" out of you lickety-split.