It's a great idea. I love how I am able to "contain" cookies to certain domains. The only issue I have is that some login pages does a lot of redirecting (bing, google, et. al) which this extension doesn't also capture. There is no way to add domains manual or wildcard certain subdomains. It the extension does see it you can't "fix it". The only work around is to turn off "limit to certain domains" but that is a pain to toggle back on and off when you need to login and such.