Can you point me to a study that says that live is healthier and more exciting for the snake than f/t? The fact that there are thousands of animals feed f/t that are thriving in collections around the world is proof enough that f/t is no less healthy than feeding live.
I am impressed with my snakes and the fact that they are perfectly designed to dispatch their prey - but if entertainment value is the reason to choose to feed live, the keeper might want to re-think their reason for having a snake.