Training a pet takes forever. Even with the mega snacks. We have all these low value snacks that are pretty much ignored if your trying to train your pet up all the way. How about a mini game where you can 2 or more of your pet snacks into a new one of higher value. Or even trade in several snacks for a mega snack.
This would make training your pet a little easier and make battle more interesting since you could change out your pets for different stats and abilities. Also I'm sure it would free up some memory for the game not having to store data on all kinds of pet snacks just sitting there.