If you go into genesis-featured-content-widget/widget.php
you’ll see the following code about a fifth of the way down the file:
$image = genesis_get_image( array(
'format' => 'html',
'size' => $instance['image_size'],
'context' => 'featured-post-widget',
'attr' => genesis_parse_attr( 'gsfc-entry-image-widget', array( 'align' => $align, ) ),
) );
I just switched $instance['image_size'] to 'full' for my own purposes and it works fine.
It’s not clean, it will erase in an update, and it certainly doesn’t affect the drop-down, but I don’t have the time to figure out how to do it properly just yet, and the front end result has zero issues.
Thanks for looking into it. I notices that It add custom image sizes. I worked around it so no rush. Just wanted to point out a feature add.