Is $4,000 to replace old copper main drain line with 2" PVC a fair price?

I asked my pool contractor to replace the old copper main drain line with 2" PVC during our full pool remodel, since we were already updating all the plumbing. My original thinking was that pulling water from the bottom of the pool would improve circulation and increase efficiency for our solar roof heating system. However, I later discovered that what I thought was the main drain is actually an equalizer line. It only draws water when the skimmer isn’t pulling (e.g., when water drops below the skimmer level or when using a UFO attachment). To complicate things, we’re also installing an autofill system, which makes the equalizer line largely redundant. I'd love to get your thoughts. What are the tradeoffs between: Keeping the equalizer line with 2" PVC and a UFO in the skimmer vs. Installing a dedicated 2" suction line from the bottom of the pool directly to the pump with a control valve? Would the latter offer better heating efficiency or water circulation? Is it worth pushing for despite the contractor’s pushback?