Frío no permite estiramiento?

The overall answer here I believe is yes - but at the cost of bad growth in general. Subpar bud production. For example - Can you grow smaller plants with 20% of the suggested lighting for canna? Yes it will work but with a drastic decrease in usable produce.. if all you care about is short plants.. it may work. But we’re growing this plant for bud. Quantity and quality. You are reducing both significantly by keeping temps low like this

in the strictest sense, maybe... but it'd cause otehr inefficiencies in the plant's chemistry. (biology is chemistry's red-headed one-legged step-sister) how long does the stunting last? if it impacts the light hours at all it obviosuly has a greater negative impact than perceived... details and nuance beyond monkey-see moneky do is needed here to answer that question with certainty, but probably causes too many negative effects otehrwise to be used effectively for what you want to do. stretching? increase light intensity.. if you cannot do taht, next time reduce area of coverage with shorter distnace from canopy so you can focus more intense light on a smaller area of coverage and avoid the problem of excess stretch... that is a sign your light is not strong enough. some crazy genetics do stretch like a motherfucker, but even those you want to blast wit more light then back off before you bleach a cola later on after vege growth ends (= stem elongation and leaves).

Cold stunts all growth, not a good idea, oversaturate in blue light to shorten intermodal spacing. Making sure to provide more than enough light so the plant does not feel the need to "stretch" for more optimal lighting.

Interesting idea but no... what that actually does is to stunt the growth of the plants, which is not the same as just keeping them short. They wouldn't develop very well and you'd have a fairly poor harvest. Best would be to do some LST. Nice try... I like to try to "think outside the box" too - but I think this is not a viable plan... but keep thinking! Good luck...