The method to use is…
In the acf_add_options_sub_page declaration, add 'post_id' => 'article' as a parameter. (post_id)
This is how the field data, as entered on the Options page corresponding to my post type, will be saved.
On the display end, display using $featured_posts = get_field('featured_posts', 'article');
‘article’ and ‘report’ are both used.
In my case, at the display end, I use $queried_object->name to dynamically infer either ‘article’ or ‘report’ post types.
Credit hube2