I use an other launcher (KISS) which uses Android adaptive icons functionality to render custom icons shapes. This feature is available since Android 8, and I have 9 on my FP3. Many of my installed apps support it, and it is really easy to make.
Knowing this, I was very surprised most system apps do not support it. They really should and the default launcher should use it as well, this is the recommended way to create icons (you can always provide fallback legacy icons for older devices).
Are there any plans on supporting this basic feature? Right now most system app stand out from the rest of the apps I installed. Some support it, like the pdf viewer and the camera, but not the others.
Here camera supports it, but not calendar and calculator:
Here, Feeder supports it but not Files :
Here protonvpn and the default pdf viewer support it, but not phone:
Supporting this would be a step further in the OS UI consistency.
If you think this is a valid issue, I could create one on gitlab.