I agree on the 'busy-ness' of the center section - busy, but not a distraction for me, but the overall segmenting is superb. I believe the typical purchaser will not notice the slight imperfections that we do. I like to scrutinize (privately) a line on the top and bottom left-to-right alignment of the knots. If they are good to the eye, the central cavities are usually also good. I can tell if a central cavity is not matched to it's parallel, but until I point it out my wife (who is good at picking up on my pen segmenting flaws) would not notice.
Maybe not added to your stable of designs to re-do, but mighty nice - be proud!