There’s a longstanding bug report to get window shading working on KWin Wayland.
I’m wondering why couldn’t this feature be implemented as setting the height of a window to 1px and its contents have a 0% opacity.
But I’ve never looked at the KWin Wayland code so I don’t really know why shading seems to be a hard feature to implement.
Here is an example of window shading if you have not heard of it. It’s a far more efficient way to manage unused windows than a task bar