Cold temps and short day length conspire to limit autoflower flower development outdoors.
Autos really do need 18/6 and indoors to perform to their best potential.
As primarily an outdoor grower, autos lost their appeal to me for outdoor growing a long time ago.
Harvest at about 90-95% brown pistils if you prefer a THC induced mind bending head high.
Harvest at about 99-100% brown pistils if you prefer a CBD induced, more heavy and relaxing, body stone.
Hope this helps, Organoman.