Worry about root bound? Pre flower Auto

Hmmm. Okay. So, your issue is with you waiting so long to uppot from 5l to 12 pal. When autos leave seedling stage or within days of that. They really should be in their pots you'll be bringing her to harvest on. Most will say you shouldn't even uppot an auto as it makes stress. But, while they're still in the seedling stage. They still mainly depend on taking in moisture from the air. Hence why its the best time to get it in. As any root disturbed will be not a big deal. (But even with an uppot. It sound be no breaking up of the pot structure you'll see your sub will have when you take it out. The roots should be still reaching out. (You want to make sure you've an auto upooted before roots start to wrap themselves around the pot) as doing this with seedling makes a root ball. (As opposed to seen lots of roots at the edges of your pot. The focus should be in the centre. As that's where the roots will take up the most nutrition. 4 weeks is way to late even for a fem. But with fems if left that long you can light squash the end so it starts to crumble (roots will be able to dig deep into your new pot) as if you waited 4 weeks and then put them straight in. Your roots will kinda stay there for the most part, yes there will be some moving out around the pot. But, again, most will remain in the middle. So, maybe it would of been best to break up your structure that you got from taking the plant from the pot as it was close to flippin. (Tis why ppl don't like uppotting autos at all. As it can cause an early flip) but, you've limited her size big time by leaving it that long. There's not much that you can do now that'll have a big impact if any so, all you can do is make sure them roots get the best o2/co2 you can get to them. You'll find if you can lift you plant out of that frabic pot you'll allow air to get there. (But again. It's very late to be even bothering with doing anything mad) so let your soil dry in at least once a week to make sure your root ball that'll be in the middle of that 12L pot. As air gets drawn into your root system when your sub dries from the top, and air is pult down into your roots. If more help is needed about what I said. Please feel free to mes me Good Growing

They are lacking nitrogen.