Mike: it'll probably work fine if you vent them enough and don't let them dry out. I'm just paranoid about working around glass. That's why I don't use mirrors for reflectors anymore.
For about $7 you can get a black plastic starter tray and a clear plastic humidity dome with adjustable vents on top. That's what I use and it just seems safer, simpler and easier to me. But you have shown that where there's a will there's a way. After all, necessity is the mother of invention. Please keep us posted on their progress. HSA