Close MeetMe conference


I am using MeetMe in order to connect a (SIP) softphone and a (SIP) wireless headset

When joining into the “conference” I use the A- and x-options for marking the softphone and closing /terminating the conf when the marked user (ie the softphone) hangs up
everything is working sofar

but now for the question:
is there a way to close the conference if ANY of the marked (softphone) OR the headset (which is not marked) hang up?
If possible, I would like to leave it up to the user whether to complete the call by hanging up using either softphone or the end button on the headset

So I am asking for a (non-existing?) option for MeetMe that closes the conference if ANY og the marked users hang up.