I flower my males a week early to ensure full pollen dropping by the time the girls are 3 weeks into flower.
I hit the girls with pollen starting at day 21 through day 28 and then no more. Usually takes a good 6 weeks for seeds to develop, sometimes longer so definitely don’t want to be hitting the girls 4+ weeks into flower.
Got 1k seeds off each 2ft plant doing it that way.