So this is my S25 (Nordic!) attached to my Samsonite spinner underwater with https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1. It goes on quickly, and if I thread it through the top grab handle, I don't need to cinch it tight.
I don't know if it's necessarily any better than the gatekeeper hack, but the bright blue color does distinguish it from all the other extra straps and buckles I have floating around.
Edit: I apologize, it won't let me upload my photo. I tried on my phone, and also from my computer.