Hey bulbi i know this Q is a few days old but i just wanted to chime in. 1st get job with the grow the buds look great. 2nd i know you've had auto running in this diary and they can handle different light times compared with photoperiods, but in my opinion if youre so close to harvest i feel like leaving your light as is is best so you dont stress the plant so close to harvest (not raising light hours that is.) However if you were attempting to try forcing a plant to mature I think lowering light hours can work...it definitely can with photos, I'm sure some would say autos are on a clock and these tricks don't work...but id have to disagree as autos are still a "hybrid/modified plant" and can still benefit from lots of traditional tricks and methods. If you could have manipulated your humidity...like here i can do that, cause a low humidity that helps my trichromes...otherwise ive heard keeping your temps at a moderate level will help as well. I havent personally done gg but from what I've seen most autos seem to have that sweet spot of 10-15 weeks. But i have heard the "xxl" strands can take longer than a usual auto.
I hope this gave you any useful info and happy trimming and curing to you. ✌️