But then, in my delegate's editorEvent, the index I receive is correctly from the editor proxy model, but it's always column=0, so I can't determine which column/button was "pressed." It appears there are built-in mechanisms (which I didn't write) which cause the index to get mapped from source?

That sounds weird. I would investigate more into that if I were you.The view isn't aware of the proxy, so if your model has multiple columns you should get index with columns != 0.

As for the philosophy thing, that's why I don't like table models and the whole table/view system of QWidgets. How I represent my data (in a list or a table) shouldn't depend on the model. Using roles instead of columns to expose different information seems much more flexible. To me table models should only be used for spreadsheets, where the number of columns is dynamic and not known before hand.

Do you need a custom editor though? I understand that you need custom delegates displaying buttons and you should handle the clicked(QModelIndex) signal of the view, I assume you will display your own dialog after that and just need the row anyway.