John in NM
It seems like there would be demand there, with two primary problems to solve. First is the vast array of saws available. One would have to come up with either something that would work with many or an individual design for each, and both of those require access to a lot of saws.

Second is that the potential market is a subset of contractor saw owners - those who either have ineffective dust collection or have none and are serious about buying it. There is little point in trying to reach saw owners who are content to put up with the dust (yes... guilty as charged ).

Of course, you've been through all this and probably know the subject better than do I. But I do think you should keep at it, if not with this with something else. It can be hard to do, but don't worry about the time spent on it. Even if you invent a bunch of stuff that never sells, it is still time better spent than sitting around watching game shows