Option to restore old KDE Blur effect system?

[InkstainTheBat]

This is less of an issue and more of a feature request. When switching from Plasma 5 to 6 one of the things I noticed that irked was that blurred areas didn't account for pixels outside the blurred area itself, meaning that the effect looked quite awkward when moving windows, and especially so if there is something on the very edge. For instance, notice how it almost seems to "flash" red for a moment as the window passes over the red line.
Screencast_20250114_205827.webm
The only video highlighting the difference between this system and the old one is this one here on Reddit

Is it possible to reimplement this old system?

[taj-ny]

I can do that. This will require a larger area to be blurred, so it'll be optional and disabled by default.