I've been looking into legibility issues and some such characters which quite easily can be made explicitly unmistakable. When looking at slashed zero variants there is a chance of replacing one confusable character with another by adding the slash or dot (found this
to be an informative paper).
Is there a reason why slashed zeros are not more commonly drawn with a downstroke (like in this font
, for example) and instead the variant with the slash is used that resembles above all else the slashed O and empty set / average sign? It seems to me ironic that a feature intended to reduce letter identification errors might actually increase them, so I was wondering if there is an equally problematic catch with the downstroke I am not aware of.