Yes that method would work. It is a little more cumbersome, especially in turbulence, to get the radial right, but it will work.
In the Civil Air Patrol we use the Garmin OBS function for Search and Rescue operations, where we have to criss cross the same point from different directions as we search for a missing person, etc. The OBS is extremely useful for that and will allow the autopilot to do its thing.
But I dont suggest that iFly add that just for S&R. Garmin seems to find it a useful function as it appears on all their GPS boxes.