Connection GCS via mavproxy and FS trigger

I have on copter companion computer with MAVproxy. Everything works great , connection via wifi,4g etc. There is one problem - when I connect QGC via wifi to mavproxy on copter I can use it without problem but if tablet or phone will hang - there is no FS state it stays without change as last sets of command. How to properly setup mavproxy to chang mode to RTL when GCS connectet will be unavailable / broken. (noRC connected - only GCS via mavproxy).

And next question related - if I,m connectet to mavproxy with multiple GCS which one is master one how it is determine- via mavproxy or flight controller?