If you have a linked row column then you can still use fetch_only
rows = app_tables.my_table.search(q.fetch_only(linked_row=q.fetch_only("name")))
This will fetch just the linked_row column from my_table and only the name column from those linked rows.
(you can also do linked_row=q.fetch_only() to get a reference to the linked row, without fetching any of its data)
Though, I might have misinterpreted your use case.