Roundcube lost tables formatting when copy/paste (tinyMCE)

When copying and pasting a formatted table (from same e-mail or from other apps like excel) roundcube paste the table, and lost all table formatting.

I Checked with Cpanel support today and looks like Roundcube did not implement a solution for this as formatpainter of tinyMCE is a non-free plugin (the solution for it).

Using Roundcube webmail and loosing all tables formatting is a major problem for our clients using webmail, as they cant paste into a new e-mail simple tables with original formatting.

https://github.com/roundcube/roundcubemail/issues/8032

https://github.com/roundcube/roundcubemail/issues/5638

http://non-stop-ext.blogspot.com/2014/05/paste-excel-data-into-tinymce.html

Is there a possibility to Cpanel to implement a fix or another solution with Roundcube for this basic and important functionality?

Thanks!

Steps to reproduce: Open a new e-mail in roundcube, paste a formatted table (colors, etc) in a new email. Roundcube lost formatting when pasting it. At Horde it keeps the formatting with no problems.