I like your plan EXCEPT for moving the female back to veg. The males will be first to show sex, take the male out of the group and put him in another room, still under 12/12 . When the female starts to show, put her in with him. If you don't have a room for this, you can make a temporary room out of panda plastic. This way you'll end up with A LOT of seeds. Not sure if this answers your question. I agree with  Pipes on letting them do their thing, without having to collect pollen.