I ran it the day after the patch came out, got a piece, and haven't touched it since.

Myth is way easier to farm doing the Daily High Roulette, no point in CT whatsoever. If they removed the loot lockout I would farm it, but until then, I'm not touching it once I get my one piece. I might even bail on the whole dungeon once I get one piece if it's not going well, as it's structured to kind of praise that behavior.