The main issue I would have with cutting the tips is that is how I can judge what the plant needs. I watch the tip. If the tip is showing burning I know the plant is taking as much nutrients as I can give without burning. If the burning goes past the tip, you are feeding too much. I prefer to keep my tips for just that reason.All very good points, I'm not saying cut the leaf in half though that would be ridiculous, I'm talking about a quarter of an inch, that little tip . According to him that part of the leaf does nothing so the plant not only doesn't miss it but actually is happy that It's gone. No facts to back it up but its something he picked up and "saw a results" with so he does this routinely. I do always sterilize the scissors first and for some reason feel very comfortable doing it and I don't touch a plant unless I have to like bending leaves so light can get to bud sites or taking dead yellow leaves off the bottom that's it, I'm not one of those people that's handsy with them now I'm stoned babbling lol
If I were to 'tip' I would do it in veg, as I'm sure most of us would. By the time flowering comes it's got a larger root ball, so theoretically there should be more growth in flower. But as I said, 4 clones of a mother plant 2 tipped 2 left alone on the same 'diet' and that's how you'll know.Photosynthesis is what the plants do to produce food and they use the leafs to do so you never wanna remove leafs unless ablosultly need be otherwise more leafs more ways to feed more growth more more more.