Chilli....
Apologies. I have re-read 413 emergency procedures and accept that I was mistaken about the 7700 sqwauk being accepted practice when doubt exists over the safe outcome of the flight.
I had never considered being lost as an emergency, more as urgency. I do emphasise to my students that prevention is better than cure and the importance of communication / confession if things do go 'off-plan.'
The blur here lies in the definitions and to me, lost / uncertain is one and the same.