Well, the most logical place for this would be in the LayoutChildren of the GoListGroup. But it’s not a simple method to override. So… forcing the widths of the subgraphs may be the best choice. You may want to do that just before the GoListGroup’s LayoutChildren is done… so override GoListGroup LayoutChildren, and have it set the widths, then call the base layout. Setting the margins sounds like a reasonable way to force the width.