I see what you mean with the padding. Screens cant take that much abuse from the back.
How about it clicks into place? The idea of not having to use glue, and that it can be user-replacable is a compelling one.
You could even sell blanks. A lot of designs will work, as i now understand there to be a choice between negative or positive space.
Another idea is for something that holds a uSD card, or a tripod mount, or hotshoe for example.
I know superglue (for plastic) turns liquid again when heated up by for example a heat pistol, then again thats probably a much better idea if the screen lid has been disassembled beforehand.
There are types for metal/plastic, i dont understand where the aluminium goes though. Does it affect wireless transmission much?