Why create masses of thumbs if only features images are required?

Basically the plugin does what it’s supposed to do, so that okay.

BUT:
you end up with tons of thumbnail your WordPress installation will never need and never call upon = one way to fill up your storage…

I guess the problems with this is the WordPress code and/or how WP storage is sorted. Basically with any theme update you will only need resized thumbnails of all your featured images, as they are the ones being displayed on your front page and in widgets. But the plugin creates a number of thumbnails of every image it finds! So it includes logos, header images (both you’ll never need a cropped thumbnail of!), it wants to make a thumbnail of your favicon (but thankfully fails), and so on…