THIS! EXACTLY THIS! Thank you @rorymheaney! I was looking for this answer for like 18 hours yesterday. You are a lifesaver! Nice website by the way. I love the way you implemented all of your maps. You did that all with ACF?
For me I ended up switching from repeater fields on the page template to instead making a custom post type. The custom post type served as the repeater field and the sub fields then just became regular fields within each single post. Then I just looped through the CPT with their fields on a custom page template. That way the vast amount variables aren’t all on one page in the admin area but only about 14 or so on their respective single posts. This turned out to be a better way to do it anyway and was how I should have done it in the first place.
Has this topic been abandoned? I too am having this issue. I built a page template for a client to showcase breweries at an upcoming event. There are 14 subfields inside 124 repeater fields and that seems to be the limit the browser will handle. I have upped their max_input_vars to 6000 but still no dice. I don’t want to have to go back to them and say “Sorry that’s all it can handle.” If I had known this would happen I would have made the breweries into their post type and looped through them like that. Will this issue ever be resolved? Is there a way to show like 20 repeater fields and then paginate the rest in the admin area? Or do something similar to what was done here (http://sevenspark.com/wordpress/speeding-up-the-appearance-menus-screen-in-wordpress-3-6) for WP menus prior to 4.3?