BM's legendaries seem really weak, where Marks seems to have really strong legendaries
Only if you are planning to risk total agro from each and every group mate, sinse it will mess with other damage dealers rotations and DPS, as well as tank positioning. You might squeeze out a couple of % DPS for yourself, at the cost of lowering it for everyone else and making your tank to run around, collecting mobs again. Bad idea. Especially for Mythic+ where mobs are probably much more dangerous than bosses.