First time I see this thread. I was going to comment to reduce the top to 1 or 2 leaders, but you did that already. Another think to consider is that not all "flat top" branches need to be at the same plane, you could bring some of the leaders down and out, then empower that first branch down from the top on the left to be another "leader". The problem I have seen with my BC is that if I leave more than 1 leader at one location it will swell too quickly creating inverse taper. I did that mistake with the twin trunk I am creating now, so I will leave it as is this season, to help thicken the base and do another chop this spring and manage the buds as they come out. This things pushed buds all over the chop area, and I didn't notice till it was too late. And this was also after a repot with a severe root pruning.
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