lookst like you are doing very good, i wouldnt worry about too much, if it is heat burn maybe raise the light a few inch's or put a oscillating fan more towards the top to cool off the tops of them, small clip on fans and wall mount 12-16in fans work good in small spaces like yours ..this doesnt really concern your post, but im curious, how was and is the smell of your plants in flowering?.. and did it smell at all in the middle towards the end of veg?.. just curious, im working with similar but a little bigger space, but i got 6 plants, but not feminized, my first grow, so im sure ill have some males
... thank you.. good luck... an like i tell everyone, keep it simple is the best.