Originally Posted by bradbdad
Lastly, I don't want to appear ungrateful for the advice or argumentative, but I don't understanding if the outer most skin of a 3/8" flexible plywood substrate is nothing more than a thin layer of inexpensive wood veneer. Then why would one more thin veneer layer automatically immobolize the flexibility of the flexible plywood substrate?
The outer skin of flexible plywood splits along the grain when it bends. You could probably force your veneer to do the same, but I doubt you would be pleased with the appearance.
That being said, you could be correct that the thin paper-backed veneer would not keep a pre-veneered panel from conforming to your radius. Unless you're lucky enough to find someone who has done this before -- which I don't think any of us has -- you aren't going to know whether it will work until you try it.
Could you do a test with a smaller section? Maybe cut a 2-foot section of the flexible plywood and veneer it on the flat, and then see what it does when you try to push it up into the vault framing.
This will certainly be cool when you get it to work, but it's an ambitious project!