I haven't made this exact star, but when I have an 8-point star I try my hardest to spin the seam at the center. I would for example press everything in the center clockwise. That sometimes means I get a mix of directions for the other seams, some pressed towards the background and some away, within the individual Y-seamed components.
In this example, if each unit of diamond-diamond-square is spun counter clockwise, the final center seam will then match as all clockwise.
Yours looks good though, so if you are getting the precision and flatness you want then keep going!