I know this has been asked many times in various different ways, but to my knowledge this has not been answered. (If it has, I missed it, someone pls point it out to me)

A chain shirt is useful for the mithril breastplate crowd, who have evasion but don't have a huge dex.

However, it's possible the omission of the chain shirt was on purpose to 'nerf' that specific crowd. If so, I would like to know for sure so that I can either try to live with the leather in those cases where it's possible, or not bother collecting runes at all with my medium-dex characters.

On the other hand, if the shirt will be added in the future, I'll be happy to just collect the runes to use for when it's added.