I let those ideas mull around in the ole empty noggin' with the other nuts and bolts for a while, got frustrated with dust, forgot everything I saw, and started building.
I started with some scrap MDF and plywood laying around the shop and built the back. The idea being to take the 6" dia dust collection pipe and turn it into a slat across the bottom of the back using a wedge or 3 slopped sides. A wise man once told me, a hopper ALWAYS must have one flat side so I figured maybe it is the same for an inverse hopper.
I wanted to keep the open area as close to the same as possible.
Here is a picture of the opening to the "wedge" at the top where the 6" pipe will eventually go in.
Here is the slat across the bottom where the dust will hopefully enter like a greyhound after a fake rabbit:
The bottom is on and the sides are coming along.
And finally, with the saw on it, pipe routed, and 6" blast gate from Clearvue installed.
I drilled a hole in the back and added a flange for 2.5" hose which I connected to the saw port.
The result is fairly good dust collection but it could be better. I'm going to try making the slot adjustable to be smaller and see if that improves things.
The stand is an old stand I had made and will be updated at some point.