There is a case where this plugin may generate a bit of confusion to the user.
Suppose that I've create a post where I use, for the very first time a new tag.
Following my settings, the plugin will create automatically a link to the tag, but it will actually shows ony the same post.
I think that checking how many posts are available with the same tag and ignore thetag if the value is <=1 would make the result a bit more usable.
Besides that, is a great time saver plugin!