Vet said it is unhealthy to feed BP once a week

All animals benefit from eating small items more often rather than huge ones seldomly.

It keeps the digestive tract constantly working and gives the animal a constant supply of energy.

However, snakes often become very sluggish after eating, and they are clearly in discomfort at times when digesting a fresh meal. If you feed your snake a bigger meal less often rather than a smaller meal more often, your snake will have more time to be a snake and less time to be a slug.

I think it all depends on what works best for your snake. I don't think anyone can positively say what is "better" or "worse" as long as your snake is being fed. If she insists you change your feeding schedule, you could always tell her he's on a specialized diet. I'd strongly recommend keeping his current schedule. As was mentioned already, animals become very accustomed to being fed at certain times.