No, Morrow is the only one that I know of recommending such a long break in. Actually, I think there may be other brands that use silver plated copper, I don't know what they recommend.
At any rate, apparently that's the reason their cables need such a long break in. The silver copper combo needs time to get groovy with each other. I don't know for sure, but I've got 3 pairs of their IC's, and they did take time, and sounded sibilant and off at times in my system. But once they broke in, they've been quite good.
On my most recent cable I went with their burn in service, and it did help.
At any rate, apparently that's the reason their cables need such a long break in. The silver copper combo needs time to get groovy with each other. I don't know for sure, but I've got 3 pairs of their IC's, and they did take time, and sounded sibilant and off at times in my system. But once they broke in, they've been quite good.
On my most recent cable I went with their burn in service, and it did help.