I don't really like the idea of bringing in more blight, personally, unless there's a limit to the vastness of the blight and that it can be undone/moved elsewhere.
The whole point of more blight—whatever the means of applying it—is to reduce the number of available regions.
So assuming we did something along these lines, yes, there will be a limit, but it will be carefully controlled and monitored by the devs, and increased as necessary. If it can be undone, it will not be easy, and it will only be possible if it is balanced by a corresponding additional blight somewhere else.
