I have been able to use a custom query to display information in list view by overriding get_list() to use my custom query.
However when I go into edit mode my data from the joined tables is not there. I see callbacks to override functionality before an update but not before displaying the update/edit page itself.
I'm looking for either the correct function to override in a custom mode or a callback I should use to display the data called from the joined tables that were called when the list itself was created.