If they are already pollinated, I would just leave them. It will be easier to pick out ripe seeds than it will be to pick out premature ones, and plus you will have seed stock in case your mother plant dies or something.

I had a few lower inner branches on my Master Kush with those wispy buds that ended up herming and were forming tiny seeds so I just chopped them. Its usually the scraggly undergrowth that ends up herming and pollinating, so its best just to cut it all off before you flower.