Ideally we would need:

A plug-in that:
a - allows to play with the render settings AND
b - renders a file and reports the duration of the render
Both features are available now, but in separate plug-ins.

I had thought to integrate advanced settings in the default photo panel but it was not possible at the time.
Now there is a new photo plug-in, it might be feasible for a future release. We could add a button to open a dialog box displaying the photo renderer properties related to the quality indicated by the slider.