We currently using:
Yes I saw that TinyMCE now seem to work which is great. 
Well I haven’t tampered with any files in the custom directory. So i haven’t touched the file editviewdefs.php at all.
The only thing i really modified is the modules/Emails/include/ComposeView/EmailsComposeView.js per your recommendation in this thread: No hyperlink button to create links in WYSIWYG Editor? | [emails] - #17 by p.konetskiy
Kind regards
PowerQuest