After a few years of consistently defrosting the Ice Maker and applying ALL the Samsung recommended engineering updates, I finally just turned down the water pressure to as low as possible and still fill a glass of water from the door. This would best be described as the water valve to the Refrigerator being "Just Barely On". Defrosted the ice maker one last time. That was almost a month ago. Still, no Iced Over defrost vent! WooHoo. Hope it was really that simple all along. I'll keep reporting but things are looking good. Worth trying if you are having this issue.
That's great news! We really appreciate your tenacity to get this matter under control.