Add post-type-specific moderators not working for Pages?

Whenever I associate a taxonomy with the Page post type, I can’t choose that taxonomy for either posts or pages. I tried making custom taxonomies for pages (the taxonomy won’t show up in the drop down) and tried associating both tags and categories with pages (the taxonomy is gone from the drop down list for post and STILL doesn’t show up in the drop down list for page). Is there just no way to make a moderator that is specific to a category or group of Pages?

https://www.ads-software.com/extend/plugins/peters-collaboration-e-mails/