Hey Forrest,
did you see the Nighthawk 4" dust boot for 80 mm spindle? I believe it would be effective as its opening is not on the entire foot like on the PwnCNC v7, but much smaller so should be much more effective.
If you use a 100 mm / 4" hose, what is the diameter of your Dust Deputy inlets and outlets, and of the inlet of your Dewalt shop vac?
I have already seen here that attaching a 70 mm / 2.5" hose to a shop vac with smaller inlet diameter works good. It shows a setup with Nighthawk 2.5" dust boot for 80 mm spindle.