I stopped feeding kibble as training treats because I didn't realize they were so PACKED with calories, lol I ended up feeding way too much, that was around the time I switched to raw feeding, and used kibbles for treats... was wayyy too much. then I thankfully stopped feeding kibble, ever.
But I use the frozen kong idea which I got from on here, I stuff it with Velveeta cuz Toffee loves cheese. I would also put that IN the crate becuase it sounds like Mozart doesn't like the crate much so I would want to start to make it a super happy, safe place for him. He has to associate his crate with good stuff, and I recommend playing crate games, because the foundation you build now is going to be invaluable later! I had to start crate training all over again because I only used to have him crated as a pup, but now needed him crated for agility or when I am visiting friends overnight, etc. But we are getting there, it's his home away from home.