Yes, a fan will help them develop more fiber in the stalks/ stems. You definitely have too many plants for your space so that’s a concern. I’d get them all into their final pots and then see which do the best and keep them. You could also try some training techniques that keep them on the smaller side. Check the tutorial and journals on “ sea of greenâ€, might find some of that useful. But get them into their pots ASAP those roots need the good stuff to grow big above the ground-so to speak. Strong lights that are too close will tend to keep your plants a bit shorter,often with closer internodes. But your ppfd seems plenty strong, I start my seedlings at 200 first week, 300 second week, 400 third & fourth weeks, 600 until the 6th week and then 800 for the remainder. Then no light the last three days. Hope that helps,