So these have continued growing fast, with the result that the tallest is now 100cm, only 30cm from the light. The leaves are still pointing up, which seems to suggest they're light stressed, but not any more than before, and the taller plants are not more light stressed than the smallest, and there is a significant difference in height. At the start of the week I fed them a really rich batch of worm casting tea and they've burst into flower this week, with many bud sites, which is helped by the 15W corner LEDs I added, and they seem healthy aside from the thrips which remain present, though it seems less. I'm just hoping they don't get any taller, so I'm going to feed them unfertilized water this week, and will blast them with more casting tea when they've stopped growing so they hopefully produce a heavy amount of bud. Since the start of the grow I've been rotating their position, so they get even wind and light distribution. So now that they're getting bushy, I'm spending some time adjusting the position of the leaves and branches, though not tying or training them in any way, to optimize the light and make sure the bud sites are coming through, and I'm opening the tent to allow more space for the fan leaves to come out. I still feel like they don't really need to be defoliated, but I will experiment more with that in future grows.