Topping or wait? And why ?

you can top anytime you want... What is the end goal here? Try working backward from there to decides how many branches you want to even out... how big of a space does this plant need to fill? how many vertical colas per sq ft do you want? The decision is made for you by these local parameters. in my experience, fast flower is a gimmick. You'll still need 8 weeks or more for flower like most photoperiod plants. All they do is mix in some ruderalis genes, which are inferior plants. I don't think it be a net-positive. With that said the Green Poison Fast i grew was an very fast vege growth wtih 55-60 day flower period. It wasn't very stong, but it had really nice nugs. I know for sure you treat it the same as any other marijuana plant, within common sense reason. It won't make a difference in how you feed or when you should train it. the idea that autoflowers are faster is an urban myth too. you can simply run a photoperiod 12/12 from seed and get similar results. (maybe 2 week vege would be equivalent, my best guess). So much misinformation out there... becareful what you believe. some people think they need 20 additives, singe to the plant and ice the roots while giving 48hours of darkness, lol.... really, it's just about their need to feel like they are doing something important... even if it isn't, bwahaha.