Beautiful quilt, both for the fabric choices and quilting.
First of all, my suggestion was not SITD ...... would compromise your already fragile seams even further, because of the longer hand stitches, rather than the tightness of a machine stitch.
What I did suggest was "next to the ditch" ..... meaning, just to the edge of the seam on both sides and within that 1/8". That way, you would catch the foldback of the seams and help hold things together, should the hand stitching give. Your photo example is a lovely quilting design, with the arches along every seamline. The challenge you are facing is that your seams are only 1/8", so I am not so sure you could get an arch that small that could deal with the issues you are facing.
Stippling? ... you may be more familiar with the term meandering. Stippling is virtually the same as meandering. In the following link, she equivocates the two, and gives examples of different sizes. When I say stippling, I think more of her Tiny and Teeny examples .........
What is Stippling? | Quilts By Jen