Source (required if based on other people's work): https://cgit.kde.org/scratch/vladz/kwin-effects-minimizescale.git
For KDE Plasma < 5.15:
* Download the archive with the source code;
* Create folder for KWin effects:
mkdir -p ~/.local/share/kwin/effects
* Copy the package folder to the newly created folder:
cp -pr package ~/.local/share/kwin/effects/kwin4_effect_minimizescale
* Because the effect won't be listed in the Desktop Effects KCM you have to
enable it by editing ~/.config/kwinrc:
- Open kwinrc with your favorite text editor;
- Add kwin4_effect_minimizescaleEnabled=true under [plugins] section.
* Also, don't forget to disable the Minimize Animation and the Magic lamp effect.
* For KDE Plasma >= 5.15:
You can install this effect by clicking "Get New Effects..." in the Desktop Effects KCM.