Holy shit so 1 plant filled your 3x3? Definitely will have to reconsider my grow. I have enough space for (4) 3 gallon smart pots but I guess I wasn't accounting for how bushy they get. Maybe (1) 5 gallon smart pot or (4) 2 gallons? I wish I could give you more insight on your flushing stage, I will be using sledgehammer or something similar to that, to aid the final flushing stages. Usually I let the plant talk to me when I see no further growth and leaves are yellow, it's time. Trust me the worst thing to do at this stage after all this time and effort is to chop it early, I know from experience lol.