I recently hit a big with DSL Tools, where it wouldn’t support CustomOutlineDashPattern because, apparently, its support was withdrawn as a result of GDI+ bugs. Luckily, the shape classes are partial, which meant I was able to return the support for this feature with ease:

partial class CommentShape
{
  private static System.Collections.ArrayList customOutlineDashPattern;
  protected static System.Collections.ArrayList CustomOutlineDashPattern
  {
    get
    {
      if (customOutlineDashPattern == null)
        customOutlineDashPattern = new System.Collections.ArrayList(new float[] { 4.0F, 2.0F, 1.0F, 3.0F });
      return customOutlineDashPattern;
    }
  }
}