Idea Summary
Add ability to multi-select / select all page items in APEX Page Designer Dynamic Action “Page Items to submit/return”, and anywhere else similarly selecting Page Items.

Use Case
Makes it a lot easier to program when multiple items need to be selected instead of having to pick them one by one.  Reduces errors when multiple (especially all) items need to be selected so less likely to miss one or more Page items in the list.

Preferred Solution (Optional)
Add multi-select functionality to select Page Item selector/LOV wherever it appears.