I stumbled upon a plugin that will publically display the duration and the reason for why a user is banned on their profile.
Transparency is always good, so why not add it?
(also reminder to check the permissions, this plugin adds some)
Information about locks in the user profile - WoltLab®
The plugin inserts ban information into the profile of banned users. The information is visible only for selected user groups.
www.woltlab.com