Here are some options I've considered:
- __sql__ directive in fields.ini with carefully crafted joins to be sure the same number of records is returned as the default query This seems like it would be the best option for performance, but I'm not sure how to write the query to capture multiple values in a single cell.
- fieldname__rendercell() in table delegate class with a mysql_query or getRelatedRecords() function This should give more flexibility with the display/layout, but it seems like it would be a significant performance hit to run a separate query for each row in the list view.
- custom action with RecordList/RecordGrid
Any pointers or other options would be appreciated!