Hmmmm works not really here.

extmute_off=SaveAux
extmute_on=RestoreSrc

It switches off the display when starting a telefon-call and cut the speaker.

When the call is finished it goes back du Source from AUX with a flashing "Waiting"

With:

extmute_off=Pause
extmute_on=Pause

It just does nothing when the phone call starts but
switches to Pause when the call is finished.

Its an MK2a with V3-alpha8 and hijack v455.

Regards

Christian