Holy crap. As a lifelong Mei player, I know what I'm trying next on that map.
I've been sending them into tight corners and such with no luck. Lots of people for me have seemed to wise up.You'd think people would wise up to dvas self destruct already, but i still get regular triple kills. Still no 4 tho. T_T
However, on Dorado I did get a triple at the first hold point because I sent the mech up into the air and over the wall. Didn't give them a chance to react.