If you use Advanced Custom Fields for WordPress, you may already be aware that you can hide the main content editor. This is useful for templates where the main content is actually assembled from one or more custom fields. However, this only takes effect if it is set on the first custom field group. If you define another custom field group later and it appears above the group that hides the content editor, the editor reappears. This is annoying.
To solve this problem, I have begun to define a separate field group with the sole purpose of hiding the main content and then placing it above all the other field groups:
acf_add_local_field_group([ 'location' => [ [ [ 'param' => 'page_template', 'operator' => '==', 'value' => 'foo.php', ], ], ], 'menu_order' => -1, 'style' => 'seamless', 'hide_on_screen' => ['the_content'], ]);
-1 ensures that the group always appears above any other field groups and setting
seamless means that the empty group will not be visible to users editing the page. You can also add as many items to the
locations array as you need, so you only need to define this one field group to hide the main content editor where ever you want on the site.