Don't cause stretching - most likely a better idea.
If you think lights are too close, there should be signs. I don't see your canopy getting pale, but it's not 'praying' either. Nodes would also be piling up on top of each other. If that's not freshly watered or out of strong light while taking picture for too long, the leaves should be perkier. If they are glossy or they feel super smooth on bottom, dial back nutes. K-toxicity can be an issue with poorly prepared coco - like mother earth 5kg bricks.
Otherwise, it will continue to grow taller. Each time you top or lst, it spreads resources and slows that vertical growth, even if overall growth increases. Allow one branch to grow taller and it will become dominant. Don't increase concentration or allow nutes to build up, but fed everytime in coco. If it doesn't drain to waste, you'll have to account for evaporation woth some ph'd-only irrigation occasionally to avoid problems over a long period of time.
if you need many clones off the plant, treat it normally -- top, LST or whatever you do to make a plant nice and bushy with lots of opportunities to take cuttings.
If you only need 1 or 2 each time you take some, just top it occasionally to fit the height you want. Cut down much longer than your intended clone, so you can slowly 'step up' a node for future cuts. Do that when you are pruning to maintain size too. Ensure light is hitting any newly exposed auxiliary buds.
Size of pot can greatly impact how tall your plant will get. Exceptions to that exist for hyrdoponics. I have mothers in about 1/2 gal of coco. They reach about 18", give or take. I also only feed half the time i irrigate when between cuttings. I am closer to deficiencies than toxicities and react with an extra does of nutes as needed or to get it in perfect health for a clone.
If i fed those all the time, they'd get taller even in those small pots of coco. Constantly refill reservoir of your hempy as it runs out, and it will grow large relative to pot size. It just takes more irrigations per day, which is fine with an automated system. If the plant has teh roots to drink it, it will drink what you provide, hence in hydro you can make a plant very large relative to volume of your substrate when compared to similar volume of soil.
Feed constantly without causing concentrations to skyrocket, and it will grow all you want. At some point it will get rootbound.