Can honestly say I never counted nodes. I see so many growers these days going 12/12 from seed- or doing a 3 week veg from seed...they are not waiting to full maturity to flip to flower cycle. That being said I recommend going for as long a veg time as is possible taking into consideration your light size(lumens), growing space, strain, and method(I.e.scrog, SOG). Sativa doms stretch a lot at flower & this is important to consider when planning a grow...Indica doms tend to stay shorter & bushier especially when trained in a SCROG. I can see doing a short veg in a SOG setup but usually it's using matured clones. Anyway to answer your question I'd say you COULD flip at 8 sets of nodes... That is 2 sets of fours on an untopped plant but you should plan for a long veg to increase yield. The extra few weeks will make a huge difference. Consider also the awesome power of laying down & tying your tall girls to a SCROG net or screen to make all those small bottom branches into colas. LST and supercropping slow your growth rate but can also increase yields exponentially. Do a bit more research & be patient. Like Tom Petty says the waiting is the hardest part