RQS - Northern Light & Purple Queen

Starting to get a bit cramped in there now, can no longer see the pots and I can hardly tell where one plant ends and the next one begins! Is it time to flip to flower? I'll flip them to a 12/12 cycle tomorrow, and will defoliate the lower leaves, I won't take off too much as don't want to go overboard. I'll see how they recover and then look at possibly defoliating / lollipoping further.