We have not started tracking, however what Slamdunc said about the food is spot on. The dog will not starve himself. If he realizes the only way to get his food is to play your game, he will play your game. It does take patience, but it should build his food drive.
There were a few times where I just had to walk away from Katsu without giving her breakfast because she would refuse to do what I asked (this wasn't a case of not knowing either, we've worked on it before). When I would try again later, she definitely put in the effort.
I too would recommend finding a trainer/club to help you.
I didn't see the comment about him being chronically underweight. I would be careful, but still try the NILIF route.
With the ball, it sounds like his drive goes through the roof. You will need to work him through that so he knows he can't just ignore you because his favorite thing ever is nearby. Try a few sessions with the ball where you attempt to fine tune, if he doesn't get it, say "oops!" or "oh well" and put him away (crate, etc). Wait a few minutes (5?) and try again. He should realize he needs to listen to get what he wants. Still will require patience.