chasv77answered grow question 5 years ago They way Iook at it, if you are just 3 weeks away from harvest, removing "only" those large fan leaves to uncover other "growing" buds is OK.
I assume those small leaves protruding from the buds are absorbing the light waves needed to keep the buds fattening up. Hopefully there are enough lower fan leaves left, to help those less unfortunate popcorn buds.
You could also try folding/tucking those larger leave out of the way, if you don't like trimming this far into flower.