I have tried orbit select before and never had much joy with it. To give a fair response to your query I had another go, and found that you are right (and in fact answers an earlier request for a left foot camera and right foot camera). What I had been doing was applying it to cameras in use, mostly dolly cameras. It doesn't work. I just used the main camera in a scene I happened to have open, selected a foot, clicked on 'frame object' and used orbit selection, and it worked. So you are correct, I was just never using the right camera. Cheers!