the hairs dont have much if anything to do with harvest its the trichomes(crystals) your best bet to get more yeild keep it on 12/12 and harvest a extra week further than your thinkin of doing now.... peace
I was curious about the same topic and incidentally posted a similar question right above yours. There are a lot of different theories in regard to light cycles during budding. I was curious as to whether the light period or dark period or both affected/triggered the plants flowering cycle. Anyway, I found these interesting articles that might be helpful to you.