The problem is while tempered is stronger, when it fails it's catastrophic. With non tempered plate glass you might get some time to do "something" becuase you might have only a crack. If tempered fails, it's thousands of tiny pieces. All the water will drain very fast.
Shower doors and car door windows are tempered. Ever seen a broken one? Then you know what I mean.
Putting some egg grate or a sheet of acrylic down is very prudent.
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