Has anyone done a hidden city on one of these? I’m looking to book LAX - JFK round trip, however I need to stop in a connecting city on the return segment, with my companion continuing on to LAX.

I’m the certificate holder, so if I miss the final connecting flight to LAX, is there a likelihood my companion’s ticket on that leg is cancelled if I don’t board?

I really don’t have any other use for cert except for this possible trip.