Is your goal to get them as close to 80" from the floor as possible, without going over? It just depends on the plant. Since they're clones the original grower/supplier may be able to tell you how much they stretch. Otherwise, since you have two of each, you could start flowering one soon and wait for the other to grow more.
I have one that grows to 70" no matter when I switch to flower, at 12" or 30". It just doesn't want to be any shorter. I have another one that generally only grows another couple of inches after the switch.
80" is a lot of height. You can grow trees in there. You should be OK no matter what you decide. Sorry I couldn't be more helpful.
use lst (low stress training) on the taller ones, bend them over and tie them down till the new growth starts to grow upward on its own. then do it again with the new growth, you'll end up with a bush.
you can use a scrog net without actually scrogging, just to hold the plants down till they start to grow the way you want them to.
i've had plants growing in complete spirals, maybe 5 feet tall that would have been over 8 if they were just growing straight up
I see your concern now. Yeah ^^^^^^^^^^ this is good advice.use lst (low stress training) on the taller ones, bend them over and tie them down till the new growth starts to grow upward on its own. then do it again with the new growth, you'll end up with a bush.
you can use a scrog net without actually scrogging, just to hold the plants down till they start to grow the way you want them to.
i've had plants growing in complete spirals, maybe 5 feet tall that would have been over 8 if they were just growing straight up