SUMMARY Should be able to make & receive a phone call directly from the pc. Just like Microsoft's phone companion does: https://www.cnet.com/how-to/you-can-now-place-and-receive-android-phone-calls-on-your-windows-pc/ I guess hat seems to work over a Bluetooth connection, where the PC functions as a headset. EXPECTED RESULT Should be able to make / receive calls on pc
Just an idea, it may be worth looking into how Android Wear (and other smartwatches) handle redirecting calls to the smartwatch. Especially for 3rd party smartwatches (like the huawei GT2 pro I am using) I am pretty sure they don't rely on standard bluetooth voice profiles. If I'm not mistaken KDE Connect currently uses wifi / vpn connectivity exlusively, so going the bluetooth route for voice calls could make it even more complicated than a "custom" redirect solution.
All implementations for Android - WearOS<-->Phone and Windows<-->Phone rely on Bluetooth using HFP protocol to for phone calls and controls. We already have hfp_hs audio working with both pipewire and pulse. The other major component is controls. Right now the native impl of pipewire doesnt expose any of these in any way. The next option is hsphfpd. I documented some of my findings here (https://github.com/GSConnect/gnome-shell-extension-gsconnect/issues/1159) but have been too lazy to work on testing to see if this actually works.
*** This bug has been marked as a duplicate of bug 410149 ***