Fractal settings apply to the whole world. I considered what the MojoWorld folks describe as "parameter bombs", but the general case is a bit unpleasant to implement, let alone describe how to use. It would require what amounts to a selection for each area to specify how to fade in the new data and a new fractal generation state for each area. Execution time will now go up proportional to the number of parameter bombs in place. And there would also need to be a place where users can access their list of parameter bombs. In short, a major amount of development and explanation time for a feature that would most likely get little use and likely require a lot of tech support. I'm not saying that it wouldn't be useful, just that I think that there are more valuable targets to use my (very) limited time on.