I been using linux for more 25 years, KDE used to be a great working environment for me especially because of how it handles the windows focus, raising and order... until last month, I was still on custom build of CentOS 7 that I was modifying over the past years, however, I recently updated the system and decided to go with a new stable system for working environment, and using the nice KDE Plasma 5.27.2, and here is my feedback, and concerns if you allow me...

1. The frameworks and Plasma are great, with all its enclosed apps, however, I noticed that there is a bunch of very nice features for a window manager, but didn't pay enough attention to how these are going to affect other applications in a professional working environment, especially the applications relying intensively on the GPU and 3D graphics.
* my suggestion here, make sure that applications like maya, blender and houdini are functioning as expected on the system, then everything else will do, I believe.

2. It's very nice that plasma gives better support scaling of the interface (like 150% or 175) in a way that was not possible with xrandr, however, it seems that the methodology you used didn't consider that many applications will not work as expected on such scales! When the application queries the screen dimensions, the returned values are miss leading the apps, especially on 3D viewports, you will notice the viewport is rendered smaller than its actual window window the display scale is greater than 100% (I wished to attache a screenshot showing the issue), you can have the same issue also if you try to record the desktop using ffmpeg

3. Pen, touchpad and screen touch are not mapped correctly to the monitors, although it does on gdm and inside gnome, in plasma, we have to configure it the settings (only in wayland, in plasma-x11, the feature is not there, and I have to do it manually with xinput), I don't see a reason why such feature is not available to plasma-x11 as well.

4. I'm running a regular installed framework and plasma, however, at the beginning I was trying to run it by compiling it from source, the compilation went fine, however, I failed to have it work! The configuration of the system is not handled properly by the installed packages and I failed to figure out how to fix the issues where plasma is not able to see the core modules and apps needed to run (only black screen and mouse is showing up), although all apps are ok and can run if I run them inside gnome! It's about the starting scripts configuration and envvars I believe.

5. The interface is doing to much work and seems heavy processing, the interface response is very interactive, but unfortunately not as smooth and fast as gnome (which I don't find it good for my work environment due to the window manager, buttons on the bars, and because it doesn't have an option to allow using the window without raising it)