I didn't read the OP but one pet peeve of mine is the uppercase I vs. lowercase L in sans-serif. Especially in contexts like randomly-generated passwords which you have to manually copy for whatever reason. Does the article address this in any way? Or is the context limited to "real" language where that's not as much of an issue?
Perhaps, a well-designed random password generate should not use 1, l, or I. Or 0, or O. (I know mine don't).
It's surprisingly rare for fonts to be careful to distinguish not just Il1| but also 0O 2Z "'' 5S B8. I typically set my system font to something that does, like Atkinson hyperlegible.
That's only a problem with some sans-serif fonts. This very site is using a sans-serif and the capital 'I' has bars in either end so it's not confused with 'l'.
Some sans-serif fonts do add little flourishes to some letters, like 'l', to further distinguish them.