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Some of those curved glass DE hones also had a flat side for straight razors IIRC.

When you press down on the DE blade inside the glass it flexes flat so the edge is not actually meeting a curved surface as you might think.

It is not an issue for the function of most stones but if it concerns you you can use another flat stone to further polish.
Nagura & all stones should have lightly chamfered, smooth edges but the...