you might be able to super crop. actually, iv read, and seen on youtube how people will supercrop three weeks into flowering. It's in FAQ's under experienced cultivation or somthing like that, you'll find it. All you have to do is take the stem in between your thumb and pointer finger and twista and break the tissue within the stem, but not completely to where its hallowed out. and it should actually bend over at a 90 degree angle, at least thats what iv seen on youtube where this dude had a garage full of dank plants growing, and he KNEW his shit. The stem will actually come back twice as strong and increase yeild, i tryed it once on my first grow but did it too early(like 2 weeks into flowering) so i did it again on the 3rd week, mistake, and the stem got so beefed up and thick it actually busted a seem in the stem a lil bit so its true that it comes back twice as strong, 3 times as strong in my case lol. but do your research on super cropping and make your decision but no the 1st three weeks into flowering is when all the vertical stretching takes places, from week 4 on almost all bud production. Hoped it helped, but no dont do any cutting once in flowering, that'll really devert its energy into healing and repairing the cut area, i think you'll be most then satisfied if you do choose to supercrop