It would be nice if characters could show a tooltip like the buttons. Now you can't see a real difference between – and −, so a tooltip telling you that the first one is an en-dash and the second a minus would be helpful.
Actually it's possible to add a tooltip via
'characters': [ ["<span style='padding:0px; margin:0px; border:0px;' title='tooltip'>character</span>", "character"] ]
but this is really messy.
Version: unspecified
Severity: enhancement