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The first point in the generated polygon is the location returned by GetLocation when used on the object. This also appears to be the "encounters default location" when trying to find a space to spawn creatures (if it fails it just uses this spot). You can find the initial point by using Focus On Object and zooming in - that is the point that is the encounters location/position.
You can copy and paste placed encounters (which copy any edits made); blueprints then can update every instance of them by selecting Update Instances under Advanced.
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