Perhaps the main issue preventing me to switch to Plasma Wayland is the lack of support by KMail.
The message window of KMail, when using it in Plasma Wayland, shows always the background, instead of the message.
Now, I reckon this is a well-known bug, but I'd like to know if there is any perspective on the correction of this bug.
Thanks.

Please describe your problem here to help the developers:

Bug 397825 - [Wayland] Message viewer displays only a black rectangle

https://bugs.kde.org/show_bug.cgi?id=397825