Idea Summary
APEX has a great history of extensibility. One feature that native components utilize but that is inaccessible to region plug-ins is access to the LOVs defined in the shared components. The workaround is for users to input the query again in the column, which is a bad pattern.
Use Case
Region plug-ins that allow the input of data where a select-list-like input is wanted and a LOV is already defined.
Preferred Solution
New Region Column type or add a switch that enables the “List of Values” section the Interactive Grid has to the type “Region SQL Statement Column”.

This section should then appear in the Plug-In column configuration:

A nice API implementation to fetch the records with APEX_EXEC would be nice too.