This may not be the place for this question, but maybe someone has some experience with this.
We are looking to help identify some expired posts/events in the admin area of a post. We are using a relationship field to pull in Events from an event plugin and it works great, however it doesn’t remove expired events. No problem, but we want to make it easier to identify the events that have passed by doing a query and getting the IDs of past events, then styling that entry with a faded red background.
We were able to do something similar with another CPT/ACF field, but this was on the main post listing and not inside the editor.
Here is the HTML that is produced for this particular section: