I've done this before with a really stretchy prolifically branchy keeper pheno.
Used square-ish storage containers, cut about a 2" hole through the lids about 2/3 to one side, stuck a clone in each, turned it on it's side, drilled a few holes in the 'top' sides for watering, and grew them out the sides of the containers and trellised them espalier style or vert method, nice and flat like a wall, all the tops sticking through one side. Then when they had filled the trellis netting I turned them on their side and ta-da instant scrog. Filled the holes in the old 'tops' of the containers (which are now sides) with cutouts of camping mats like the stuff used for cloning collars although tbh it wasn't really necessary.
Had four of these in a 4x4 tent using 2 stacked 400w HPS to get stretch vertical style, right to the top of the tent with the filter and fan outside the tent sucking air through the fan then out through the filter. Then when they were ready they would get reoriented and a few days to turn upwards before they would get flipped in another room. They would then get the first 3-4 weeks of 12/12 under MH to minimize stretch then back to HPS til they were done.
I had tried normal scrogs with this strain but it was just too messy and took longer for a lesser result. Using HPS on the vertical scrog part would enable me to fill the trellis in and spread quicker, it was really branchy so amount of tops wasn't a problem. On average about 3.5 - 4 weeks to fill the net satisfactorily.
That strain is now long gone to the Borg and I have switched to more conventional horizontal scrog using LED, but this technique does work with the proper implementation. I was using it because of strain phenotype and space requirements and most importantly it was a faster means to a better result for me.