If default audio device is not the phone speaker, phone ringing should emit from the default audio device AND the phone speaker in addition
If default audio device is not the phone speaker, I suggest that phone ringing should emit from the default audio device AND the phone speaker in addition. This is also what Android apparently does:
Currently, from my tests (it has however been a while since I was called so my apologies if this has since been addressed) phone ringing will only output to the default audio device no matter what it is, which means that plugging in a headset and forgetting about it (& not wearing it) means that effectively phone ringing is muted which is probably not what users expect since especially Android doesn't do that. Hence my suggestion to address this. If possible, the ringing volume should still stick to the current system volume bar, however.
(Just for completeness, I also had a downstream mobian ticket on this: https://gitlab.com/mobian1/issues/-/issues/276 )