I have shapes that have custom ports as Spot Panels on the edge. But they are behaving incorrectly when the shape inside the parent panel is Ellipse / Circle.
Here is a JSBin that does a minimal reproduction of the issue I am facing - Example of Spot Panel Ports
“Auto” Panels are meant to size the main object around the other elements of that panel. Basically, to provide a border. GoJS Panels -- Northwoods Software
Note in that description about when the main element is a Shape that is a figure. Each named figure has default values for spot1 and spot2 that ought to be appropriate for that figure’s geometry. In the case of “Ellipse” and “Circle” the two spots are such that the rectangular area of the enclosed objects will be within the ellipse/circle. The same is true for the “Triangle” figure.
But you can set Shape.spot1 and spot2 to be whatever you want. For Circle/Ellipse, set them to go.Spot.TopLeft and go.Spot.BottomRight, respectively.