Nicely done plugin, has all the needed features. Thank you.
One setting that I'm unable to get working properly is the thumbnail size. The rendered thumbnail is always "square", and its height and width is the "smaller" of the height and width values from the widget settings.
So if I set height:50 and width:90, the resulting thumbnail is 50x50.
Or if I set height:90 and width:50, the resulting thumbnail is 50x50.
I ran the Regenerate Thumbnails plugin but it had no affect.
I'm using the plugin default CSS.