S&W had one type of trigger stop on K frames and a different type on N frames, if I recall.
The N frame type was a rod inside the rebound slide, and it was never the subject of S&W's advice to remove same, and I doubt that is what Mas Ayoob was referring to when quoted by the OP.
The type that should be removed is the type that protrudes through the back of the trigger guard, and which is held in by a screw under the sideplate.
That type could become loose and rotate around, locking up the revolver. The stop was redesigned making it difficult or impossible for the malfunction to occur, but when re-introduced after the design change, the factory no longer put the device on revolvers with 4 inch or shorter barrels.
Eventually, I believe it was discontinued altogether, as Bullseye shooting fell out of favor as more shooters took to the "action" pistol sports.