"Anyone tried this approach?"
Just about every concept you can think of, has already been long tested and detailed by the folks who make the glazing. Often available online complete with technical drawings, on their product web sites.
A frame that distributes stress, is still creating stress. As that cycles the glazing will develop stress cracks (crazing), and the universal solution from all the makers is to emphasize that the mounting needs to *eliminate* stress buildups completely. Not distribute them, but eliminate them.
Lexan, plexi, whatever from whoever, the bottom line always comes down to the same few "right" ways to mount them, which will eliminate stress problems and seal against leaks--if they are properly implemented.