The Shulchan Aruch concludes OC 11:14 by recommending the practice of tying Individual strings to ensure that they don't come undone, even saying that "the custom is" such.
Yet I had never heard of such a practice before seeing this Halacha, nor have I seen anyone wearing tzitzis or talleisim tied as such, nor have I seen pre-tied tzitzis or talleisim tied as such. Do any major groups of Jews still practice this custom? Why has it fallen into such disuse, if not out of practice entirely?