You have to share what a flanged binding is. Is the flange next to the binding or is it a type of binding?
When I put a flange on the edge of a quilt next to the binding, I always baste stitch it on Just shy of the 1/4" seam and then add my binding.What are you doing?
I think your stitch will be fine if you are adding the binding after the flange.
Please describe more.
peace