KDE

I'm trying to add margins around all maximized windows (so that it matches my custom taskbar which also have small margins all around), any ideas how to achieve this? I tried doing a KWin script, but even though it installs and activates, it doesn't work, not sure what's wrong. Also I have suspicions there might be easier ways to do it. This is my script attempt:

workspace.clientMaximizeSet.connect(function(client, h, v) {
    if (h && v) {
        client.frameGeometry = {
            x: 0,
            y: 4,
            width: workspace.displayWidth - 4,
            height: workspace.displayHeight - 8
        };
    }
});

Found solution: I already have panel colorizer widget for KDE Panel and it turns out, I could simply create extra panels on top/right/bottom edges with panel colorizers that allow to make them fully transparent and have custom height/width. And for windows to not lose borders/rounded corners when maximized I found a flag in "Window Decorations > Breeze" options.