I would like to report something that probably is a bug.
Since SketchUp 2017 we have had better offsetting of faces which automatically “dissolves” redundant edges at difficult shapes, so that offset is nice and clean, self-intersected and causes no mesh errors.
Usually this feature works fine but in this case my face offset turned to very weird course. Please see the image and attached model.
I used no welding. I am aware that curves sometimes cause problems. So the outline of my shape simply consists of edges. Yet if I increase offset above a certain value, the face offsets unevenly, to the worst point when the output face intersects the original one!
Perhaps the face is somewhat ill-shaped but I inspected it and found no mesh errors.
Made with SketchUp 2020.
offset issue.skp (128.8 KB)