Watson ... There's another way ........ first my back story on flange bindings!
I did a few flange bindings. Loved the effect of the narrow stripe on the front. No problems with SITD of the flange. However, where things can go awry is where that little stripe, even as little as it is, can flip flop around, not lay flat and really not look so nice. Then, once washed, more problems.
I've now done a few flange bindings, where I hand stitch ... but on the front of the quilt. Machine stitch to the back as per the normal way for flange bindings, then flip to the front. Now, instead of SITD of the flange, I just pull it flat and hand stitch at the outer edge. Using a ladder stitch, I can make that stitching almost invisible. I'm happy with the look, and no loose flippy floppy flange strip any longer to bug me!!