The attachment method shown in the installation video has worked well for me on a couple of pairs of shoes. They've been very secure.
However, I have a pair that didn't lend themselves well to sugru due to shape and texture.
This is what I ended up with after 3-4 runs, placing and removing the runScribes in the cradles.
Sugru can be layered, and this seems to work pretty well. I applied a thin layer of Sugru to the shoe and let it cure.
After verifying that it was securely attached, I used the procedure in the video to attach the clip to the shoe, with Sugru adhering to Sugru.