Prior to this new Firefox 57 version I had for years happily used Thumbnail Zoom Plus.

It was fab! Customizable, and worked exactly as desired on more or less every site visited (renowned or small/niche).

This extension unfortunately doesn't seem nearly as good.

Having visited only 2 extremely popular sites so far to test it (Google Images and Ebay) I'm very disappointed to find it won't enlarge the images on the Ebay site.......which means now having to get used to the tedious (previously unnecessary) process of actually opening the sale page for an item every time I want to get a better first-impression look at it.

The failure rate for me of this extensions usability is currently 50%.

If this fails to work on as popular and ubiquitous a site as Ebay (Really?!) it inevitably makes me fear that failure is going to be all too common an experience with this extension.

And I'm consequently already having to look for something else/better.

"Progress" can really suck sometimes...