Oh, that one.
Two.
Factory settings can be restored by the upper of the tiny buttons on the lower left of each settings window (plus save and restore customs).
In my (topicstarter) project, the max reprojection error I get after cleaning it with the competitor is 0,5.
When I use that in RC, I get several components.
So no good.
I usually use normal with factor 2.
More will not help because I will loose detail in the corners.
I have not tried to use exif grouping yet because in my cases it often does more damage than good.
But I shall give it a try when I get around to it again.