The 'Most Used' tab in the categories meta-box is the one that can be seen in the Edit Post section. I want to replace the Most Used tab, with a tab that lists another Custom Taxonomy, or edit the existing tab to display the Custom Taxonomy.
I have already created my custom taxonomy, and have spent a lot of time trying to modify this little section in wp-admin/includes/meta-boxes.php that pertains to wordpress' meta-boxes, and can be found at https://developer.wordpress.org/reference/functions/post_categories_meta_box/, and I have gathered that I need to make a change at line 440 where
$popular_ids = wp_popular_terms_checklist($taxonomy);
I suppose I might have to change $taxonomy to something else, possibly the custom taxonomy that I have created, but I am clueless about the syntax or the variable that might replace it.
Any help would be appreciated, even something that might point me into the right direction.