Hey Jesse,
well your 7 hours long Sprint is certainly interesting in many aspects, though I think the title of your article “How To Organize a Design Sprint” is a bit misleading:
Google Ventures ran 150+ Sprints, and tested all the variations before writing the eponymous book. I’ve personally tried a LOT of different formats… to finally discover that 5 days is actually the way to go.
In order to guarantee a ROI (and not waste anyone’s time), you’ll need to create a proper prototype and test your hypothesis and this does take a bit of time.
Why not just call it a “3 days workshop inspired by the Design Sprint”?

Hope it helps