@simonyrl Sorry to hear you're having troubles. Unfortunately with Canvas Render Mode Screen Space Camera only the first pass (the outline pass) of the two render passes (outline pass, then normal pass on top) is drawn by the Unity render pipeline. Unfortunately I'm not aware of a fix for this while still using only a single shader.
What you can do is render the same mesh again manually via a second GameObject. So you would have the normal SkeletonGraphic object with the default material and have a second GameObject for only the outline.
This is what the RenderExistingMesh example component is intended for with a MeshRenderer, but unfortunately is not compatible with SkeletonGraphic and CanvasRenderers. Please find below a new RenderExistingMeshGraphic sample component, which supports any MaskableGraphic and can be used for SkeletonGraphic.
