I think it can confuse users even more, when min/max length is checked it counts chars in HTML string with all tags, so users will see other number in counter than what they typed and will be confused.

It's already possible to display chars counter in Froala editor - https://www.froala.com/wysiwyg-editor/examples/character-counter by adding this module in Froala settings, but it isn't accurate for this case since it don't count html tags. However there is small modification for this Froala plugin to count HTML tags.