I've done this and usually see buds a week sooner then normal. Your tops will be light colored when you turn the lights on for a couple days but don't worry they darken back up.
@mwhite9829 what are your thoughts about flipping like this?
Any to me I can, I do. There may be some strains out there that don't make any difference, but I haven't had one that it didn't. When I first tried this I had 4 plants, 2 of each strain. Put 1of each strait to 12/12 and the other 36 hours of dark. I had flowers formed a week sooner on the plants I put in darkness. First time I did it I got a little nervous with how light green the tops were on those plants, but they just fine.
Almost every time I've done it my plants seem to show pistils sooner.