Question about taking cuttings

Hi there everyone. I usually do autoflowers but a certain seed that i have run appears to be a photoperiod, and has been vegging for the whole 10 weeks that the other autos have been growing and finished. So im left with a huge photoperiod plant in veg. Im wandering if you can take big cuttings, like cut the 6-7 main branches off from the bottom, apply root gel, pot them and maybe veg them for a week then turn the lights to 12-12? Is this possible to do with such big branches? The branches will be about 400-500mm tall? Thanks guys have a great weekend thanks for your help

Yes but smaller is easier. Id do 1 foot cuts max. Theyll prolly veg to 2 feet in a week or two after rooting