Some third-party applications, for example Bitwarden, GPU screen recorder and many others use the system tray. In plasmashell, a decision was made to represent tray entries with symbolic icons, which is very cool design-wise. If an application were to create a tray entry, instead of its usual xdg icon, a -symbolic suffixed version of that application’s icon would be used. Unfortunately, this mechanism seems to be hard-coded somehow, since adding a symbolic icon does nothing. The icon shows up in kdialog --geticon, and is possible to use in a .desktop file, but the tray is still a colored icon. I suspect this has something to do with the way themes are compiled.
Is there a way to extend the symbolic icons? If not, how difficult it would be to implement fallback as I’ve described it?