Idea Summary
When saving data from grid/form I can't use the DML Error Logging table, so sometimes it is impossible to get problemtic values (Validations can't handle everything). It is specially problematic when the grid/form is based on a view but it is storing data into a table.

Use Case
When you need to store values from user on error for investigation where is the problem.

Preferred Solution (Optional)
Add field "DML Err Table" either to Rendering - Region - Source under Table name or even better to Processing - Processes - Settings under Table Name. Then user can write the name of the DML Error Table which will be handling the errors and under that one more field like "DML Err Value" with a value/item which will be passed to the handler. 
You would need to change the INSERT/UPDATE/DELETE queires you generate now and just add 1 more line (and sanitize this values ofc):

IF :DML_ERR_TABLE_NAME IS NOT NULL THEN
    q := q || ‘ LOG ERRORS INTO ‘ || :DML_ERR_TABLE_NAME || ' (' || :DML_ERR_VALUE || ')';
END IF;