Sometimes, when working with WP, extra queries are inevitable. Generally, when using ACF relationship fields I set them to only return the post IDs and then I get what I need using WP and/or ACF calls so that the post query is not done by ACF. And I almost always install WP Super Cache when the site goes live. WP has it’s limitations, but when you need to create complex relationships CPTs and custom taxonomies are the only real way to do it. ACF repeater fields are great, but they also have their limitations, like for instance, they are not really very good when you need to create some type of relationship based on what’s in them. The queries you’d need to run to do this would, in the end, create more of a performance issue than what you’ll see by doing it the way you’re not doing it.
