Defoliation really help?
the advanced forms of defoliation, not just lollipopping, but well beyond that are really controversial ... see the long running debate in another icmag thread is. Some will swear by it, but I've never seen anyone prove in a true side by side demonstration that it's better to disassemble your plant as it tries to grow into an adult. Up to you, but I'd recommend experimenting with it.
Lollpopping .... I take the really obvious lower ones right about a week into flowering and they make great, fast rooting clones. I'll go back through and get any remaining lower branches that obviously aren't going anywhere, as others have mentioned in this thread, about 3 weeks in.
Great question by the way,
rabbit