True and agree with the half side cambium, even still usually the plant reinforces and builds in very little time, plus when using "elastic" rubber bands im only doing as tight enough to hold in place, not actually tight which would cause issue, which would be another wrap or two.
As for resisting extra root space, Very easily actually. Keeping plants small is ultimately dictated by their root mass first and foremost, if i did run bubblers or flooming techniques and ran roots in the res the plants would just become an absolute disaster as they would definitely out grow the space in no time so it would be non stop pruning plucking training and the works. Plus with the amount of water they go through id be running a secondary reservoir to keep the small ones filled to keep the roots submerged and happy, as right now i run my reservoirs to pretty much empty before refilling, and that wouldn't be good for the roots, mind you they would be making air roots in the low states.
Now don't get me wrong this round is a jungle anyways and happened badly this time around but isn't the intended setup or desired outcome for it. Ideally its to run small enough media volume where 4 plants can fill the space with little assistance or involvement apart from a top flop say a couple weeks in to level things out. This rounds mess was mainly due to watering frequency changes allowing the plants to grow quicker than expected and the Blue Dreamatics are a lankier sativa leaning plant that i wasn't necessarily expecting or planning for as really you don't know till you grow them.
As for autos, the good ones are way different now, use to be a photoperiod only grower, mothers/clones/revegges, but i wanted to try out the newer autos in a goal to keep an open mind about things, and how things change over time and what may be my old assumptions or past knowledge/experiences aren't necessarily correct anymore also was looking for a way to fill my partially vacant veg spaces.
Needless to say a bunch were junk but some really surprised me, since then ive gone only auto because of those surprises. I see promise in them and love to grow from seed, but when i can run more plants in less time "last round was 63-66days from breaking ground" whereas a photo tack on an extra 2-4 weeks, yield is more even in a grams/kwh comparison with photos factoring in veg time too, and potency to me is no difference anymore in the good genetics. Only downside is you have to make seed, which to me is a fun thing to do, and you also get some variability in that unless your doing your own inbred lines which is no different than photos from seed, but again i enjoy having different phenos and plants that i get to run through.
So all i guess i should say is keep an open mind as doing so has led me down this path which has been a fun experience.