Hi all.
I’m using KDE Plasma for some time and I use a lot the window preview thumbnails, because I’m used to them from Windows.
But on Plasma, the usage is a pretty bad experience for a few reasons:
1.) The thumbnail of a window shows the window on hover only, when you are exactly on the picture of the window. But there is a border around, where it doesn’t work. What’s worse is that when you want to close the window using the X in the thumbnail preview, you don’t see the window.
2.) Another annoying thing is, that when moving from one window to another one, it ignores the delay, so it always makes the windows blink between the rest of the desktop (and also because there is a small border where again the preview of the window doesn’t work). Another downside of ignoring the delay is, that when you move from the window icon to the preview and you have multiple windows, when you move the mouse diagonally over another window icon, it switches the previews to this window.
3.) For some reason it looks like when hovering over 1. preview, the fade is good (from the actual window to a new window), but when hovering over the second and later previews, it fades through the desktop (which makes a disturbing effect).
4.) Sometimes the fade effect glitches, and the window keeps “blinking.”
Is there any way to change it?
On Windows (yes, sorry to say that in the Linux community), the user experience is much better.
Also in Cinnamon (Mint), I had a better experience.
I have it as working PC and I have everything setup now, so I don’t want to switch to other distro or mess with envs, but I wanted to share it for potential improvement of the Plasma 
I made a video for a better explanation: https://drive.google.com/file/d/1J7wYmQikcKhTO8sfv9uxUGa23yMnAWQW/view?usp=sharing
Thank you.