Hello,
I don't think there is.
If for any reason your Customization Wizard is still in Legacy mode, you may consider adapting the piece of JavaScript code which is advertised
here (if I understand well, the current code "simply" counts the number of characters; adapting it to cound characters or line break would not be a challenge).
Other useful pieces of JavaScript code are also available
there, even if they may not immediately fit your situation.
If your Customization Wizard is in NG mode (React), it's another story.