is the answer to your question from the article itself ...
The deckle actually is best known as the fatty part of the brisket, the favored cut for pastrami and the aficionado's preferred part of "smoked meat," the Jewish-Canadian cousin of corned beef. In fact, the deckle is any part of the strip of muscle and fat that lies right on top of the ribs,
May I clarify some of the confusion.
(1) The Beef Deckle does not have anything to do with the Beef Brisket.
(2) I have never heard of the "Deckle" being used to make Pastrami. The cuts used in preparing Pastrami are The "Navel Plate" and more frequently during recent years the "Brisket". The Pastrami served at "Katz's" and the "Carnegie Deli" are all from the Navel as that where the balance of lean to fat provides the best taste, flavor and character.
(3) The Deckle is that flap, or top cover in part of the Prime Rib that is generally removed when the Rib is make into Spencer Steaks or Rib Eye Roasts or Steaks.
It is also removed in whole Rib Roasts to meet the specifications required by Caterers and Restaurants who need more uniform tenderness and quality when serving customers. The USDA Meat guides assign numbers for all the variations insuring that guidelines are maintained.
The main reason for this as the Deckle when roasted is much more chewier then the other parts of the Rib , causing customers to complain about the meat being tough. In reality it's only the Deckle thats tough, thats why it removed.
Since most Beef is now send to source Boxed it's generally not used. Some suppliers tenderize it mechanically to use for Swiss Steaks, Stew or mostly Ground Beef. The few Kosher Caterers that still Butcher the Primal Ribs sometimes Corn the Deckles to use as Corned Beef at Buffets or as Spiced Beef similar to Pastrami but it's still has good taste, but if not slow cooked long enough to break down the collegian still is chewier.
To those of us who enjoy chewing out meat it can be enjoyable. It's most commonly sold retail at Markets offering a special of Bone On Rib Steaks. These are generally cut from the Deckle ends of Whole Ribs into Steaks, reserving the part of the Rib without any deckle to being sold at a higher price as Roasts.
That the reason those Steaks have a part thats chewy, reflecting the price retailed.
At many retailers your best value of taste, tenderness and quality per pound is from the Spencer Steaks since they are often only one to two dollars per pound then the whole rib, bone on steaks on special.
Buy a 2 pound whole rib bone in steak at $4.00 per pound = $8.00 or a 1 pound Spencer Steak at $6.00 you received about 25 % more rib eye then the much heavier cut.
I don't say that I do. But don't let it get around that I don't.