
Just tried that, with 3 different stoppers.
They do not pour at all well!
The water ended up everywhere. Each of them is a different thickness - the first one I looked at when I said the rims were too thick was the thinnest. (thicknesses of 3mm, 4mm and 7mm)
The 3 stoppers also hold different amounts.
Interestingly, two of them have polished flat tops of the stoppers, the thinnest rimmed one is not polished, but has a hot-glass marvered look of concentric rings.