How much is it consuming for you? Somebody needs to do a comparison between scrolling through Twitter for 30 mins and through Amethyst. They shouldn't be very far from each other unless your relays are going crazy or if you don't have memory to keep profile pictures in cache.
Discussion
Too much that's the problem. A comparison won't address the issue a change in settings will if we have a form of control on the feed because each request from a relay is a constant pull the feed from that & this relay. There needs to be an option to change it from constant to a customizable number if the user wants it to.
I would keep mine off & only do manual pulls like how Instagram use to have. It would just be a swipe down from the top then the feed refreshes.