John-T-53's post in Glass Tailgate ??? was marked as the answer
This is different and cool. I'd go with tempered. When you think about it, many buildings have glass doors (with no frame) and glass guardrails, so why couldn't a glass tailgate work?
It'll work fine. As long as you're not hauling a bed full of 6"+ river cobble, loose, it'll be fine (lol ... wouldn't want to do this with a steel tailgate either).
You should be able to use the bed as you'd normally would too. Put a piece of protective film on the inside - such as seismic film used on building windows - as a sacrificial scratch protectant.
Put a spacer under the latch bracket so it sits flush. And I think fully-framed would be best.