I would think that with the way an ellipsis is normally used those situations where it actually ends a sentence rather than trailing off as an incomplete sentence would be rare so the situations where you would even need to consider whether to include the full stop after it would also be rare. If it is being used to indicate that the sentence is incomplete then there is no end of the sentence so no full stop would be required.
I can remember reading books that stated that the only time a ‘fourth dot’ should be used is where the ellipsis is at the end of the sentence but I can’t remember them giving an example of where it actually ends the sentence rather than indicating that the end of the sentence is missing.