You're kidding! Apologizing for giving me so much information (and time) without charging even a nickel for consulting? On a holiday weekend? It's why this board and the folks who support it are tops.
Your war stories are not making me miss my big shop. Much fun as it was to play with the 120x60, most of the time I had put it to work to pay the bills. And babysit it, which non-CNCers find hard to believe.
I had the stock ShopBot vac setup circa 2002-3. Only mod was changing the zone layout to make it easier to switch back and forth between 60x60 BB ply and 4x8 Appleply. It was amazing. I started out masking the unused part of each zone, but then I noticed that the big Republic blower sucked enough air that it didn't matter. I'd like to get the same results on my Desktop.
You gave me a lot more to consider. I'm hoping that a plywood base well secured to the side angles will be stiff enough stay reasonably flat. For thru cuts in thin ply it doesn't much matter. If it's a problem I'll reinstall the T-slot panels or do as you suggest and get some thinner aluminum extrusion.
Your proposed hybrid BradyVac system sounds like a good Plan B. For my first go-round I'll try 2 outlets into 1-inch pipe. One good thing about downsizing is that experimenting costs a tiny fraction of what it did with the 120x60.
I had already bookmarked your great discussion of Vacuum Film Technique in case I want to cut such materials.
Thanks again. This discussion has already saved me a lot of time and materials.
Cheers,
Joel