Multiple splash scaled images not working

A DESCRIPTION OF THE PROBLEM :
On Windows, if I embed multiple splash scaled images (splash@125pct.png, splash@150pct.png...) in a jar then add SplashScreen-Image=path/splash.png to MANIFEST.MF, the scaled splash is not loaded, but if I pack all those images (scaled and not scaled) inside an external folder then launch the jar using -splash:pathToExternalFolder/splash.png -jar command arguments the scaled splash is correctly loaded.

But on Linux (Manjaro KDE) it fails in both cases, neither adding SplashScreen-Image to MANIFEST file nor adding -splash argument can load the correct scaled image.