Does everything it advertise and then some. The developer is very responsive on GitHub when I reported a bug and also kind enough to add 2 more features I requested in our conversation. He too posted a simple but informative guide to finding larger images here:
https://github.com/qsniyg/maxurl/issues/5.

Exactly what i need and it works as advertised. No issues whatsoever. It's in my list of indispensable extensions. Thank you!