I tried that. Although, considering I wanted to test it first, I made the modifications in the themes functions.php code prior to spending the time to create child themes. This resulted in no change even after changing the default image/media settings within WP and running the regenerate thumbnails plugin. Am I missing something?
From my understanding the only motivation for child themes is to avoid losing custom css in the event of a theme update. Therefore, modifying the themes functions.php code should render similar results, right?