flower topping

heyy im at week 9 in coco, tops look great but 60% of buds are premature. Tried Scrog net and used to early, so it really didnt do its job. I have 9 plants in a 4×5... already flushed half 2 times... so my question, can I cut tops to make even canopy and get rid of yellow leafs. Then nute and...