Hello , i just tried yesterday how it would be farming trash mobs with 300% MF gear in leorics manor act 1. in my first run just by bombing this trash mobs away 2 legendarys dropped in 2 runs + 1 receipt?! lolwtf... my next 10-15 runs only some decent yellows and blues dropped but then nothing. Maybe just luck?
maybe you guys can give it a try and tell me about it? i have the feeling blizz gives you a ID or something so you cant have more then 2 legendarys per day. maybe a uber farming method who knows.