There are typefaces that have lower case glyphs the same height as capitals as well as ones which have them higher. Is making number 0 the height of higher lowercase characters an ideal solution to make a bigger distinstion between capital O and 0? Also, would it be ideal for old style figures as well?
Comments
BTW if the design has weight contrast you can do things to the zero that are usually unacceptable in the "Oh"/"oh"; some people give the zero horizontal contrast, but I prefer giving it weight only on one side – and I generally favor the left side, like in Whittingham:
In most cases the aspect (=height/width) of letter \O is 1.1 (nearly quadratic) and of figure \0 1.6 (narrow).
Usually it’s in the other direction, with default lining figures being “three quarter” (shorter) than caps.
But precedent is no reason not to pursue a novel idea!
Give it a try, test it in various typographic scenarios, see if you can make it work, and decide for yourself.
The style is Scotch Modern Italic.
In a typeface I kept reworking, I made the numerals with superelliptical curves, while the letters had more rounder ones.