Not practical at all.
Undue stress issues aside, maintaining a regular photoperiod is nigh on impossible unless you have an alarm clock telling you to go switch your paper bag. Plus the size of plant that you need to have these large low branches- a plant that big is mature anyway and should be preflowering, or at the very least, you should already have taken clones off it to sex in the traditional manner.
Cloning for sex is the right way to determine sex without flowering your whole plant.