Idea Summary
When a Region (Cards, Interactive Report, etc.) contains page items as part of the Source (and the Region is refreshed as part of a Dynamic Action, automatically add all items to the “Page Items to Submit”.
 

Use Case
Sometimes we forget to add the items in the “Page Items to Submit” section. If the region is being refreshed as part of a Dynamic Action and the items are not listed here, the query will not work as expected. It might take time to debug and find this simple mistake, but if APEX is adding them automatically, it will be a quick win.

Preferred Solution (Optional)
When developer Saves the page, a process will check for such regions and add the Items to Submit if not already added.