[Feature Request] Detect extreme topology changes

[geiseri]

First, obligatory kudos for an awesome job!

While searching for villages I end up with instances where there are extreme elevation changes near the trigger location. It causes amusing situations where I have huge cliffs or ravines in the middle of them. I tried to use the "Surface Height" rule but that only gives an absolute range. Would it be possible to add a rule like "Surface Height Variance" that would pass as long as the delta is inside of a desired range? Thanks!