What would your next step be? Strip back now and flower and try control?

Keep an eye on any runoff for those little maggots grubs

those gnats will spread to all the pots, if they havent already... the life cycle of gnats is 3 weeks or so... you may not see adults creep out of the other pots for 2-3 weeks after initial infestation ... Often, they come from the store and it's not your fault. Get some mosquito bits or mosquito dunks.. if not available in your area, find something with same active ingredient (it's a safe bacteria) most likely came from the store, but sticking to a good wet-dry cycle helps avoid infestation, for future reference. They thrive in a constantly wet medium.

get bti, nothing you did would stop a gnat infestation. Adults don't actually cause any damage. it's just the larva that damage roots. Definitely don't 'strip back' unless you think it's going to be over-crowded. I'd make sure that gnat issue is gond before going to flower, and that delay might cause a need to prune them back a bit. If they were in optimal health, this would be an excellent time to flip to flower. They would easily fill in the empty space before vege growth stopped. Images for reference: https://ibb.co/BVK9cqFG https://ibb.co/cnd2VV9 So, that's 1 week into flower. You can check any of my 3 recent diaries for the pictures commented "38 days" in Week 6 to see just how much filled in after 1 week of flower. There's another 3+ weeks of vege growth coming. Technically i flipped to 12/12 schedule after 39 days, but close enough. The canopy area will at least double in size.. so 70% length x 70% width is all you need. Being able to accurately guesstimate growth after flip to flower will save you time and effort -- less pruning needed. Some pruning is inevitable, but anything cut off the plant is wasted time, effort and resources. Minimize it as best you can.

hey 👋 Defoliate the lower part of your plants to improve airflow, let your substrate dry out, keep catching the adults with the sticky traps, and when the last larvae come up once the soil is dry, you can finish them off with diatomaceous earth 👍