If he was impacted, the vet may want you to feed fuzzies at the moment because their bones are less developed and easier to digest. A healthy ball python can eat something that is 1 - 1.5x the width of their body (1x being a better goal), but you are unfortunately starting with a snake that isn't healthy.
If I were you, I'd follow the vet's advice for now. His goal for your snake seems to be to make digestion and passing feces a bit easier for a while and work the snake up to a normal routine. It won't hurt him to be fed a few fuzzies for a bit either way. Once your snake is eating and pooping regularly, I'm sure you will be able to get back to normal guidelines. You also shouldn't be afraid to call the vet's office back and ask a few clarifying questions for why he recommended this routine if you'd like.
So feeding him a few at a time wouldn't be a bad thing, or would you stick to one fuzzie every 5 days? Thanks for the reply btw!