Interesting and needed plugin if it works well!!
I'm trying it on two sites.. On one it activated and set up fine, but on the other, when I go to the setup panel, there is no display of countries.
I'm thinking that it may have something to do with some of the security protection I have in place.
Have you tested the plugin against the Perishible Press 5G Blacklist 2013?
I'll figure out what's blocking it when I get the chance, but if you know what the problem is, it will save me a bunch of time and aggravation!