Just out of curiosity, you keep calling AO Wawrinka's favorite slam. He has more wins, a better winning percentage, more QF or later appearances and more second week appearances at both RG and USO. So by every measure, AO is his second to worst slam.
Are you just being ironic or are you that ignorant lol?

firstly:
Wawa has 5 QF+ at AO: 11, 14,15,17,20
5 QF+ at RG
6 QF+ at USO
so you are wrong about RG.
Secondly wawa was stopped by Djoko in 4R in 2013. that form was better than some winners, let alone QF-finalist at AO. that makes it 6 runs.
43-15 at AO vs 44-15 at FO. big diff. whoopity do.
AO 14 - he beat Djoko, Nadal and Berdych.
A clearly tougher draw than RG 15 and way tougher than USO 16.
A tiny bit more consistent at USO than AO, but his peak level at AO is significantly better than at USO.
4 prime level runs at AO: 13,14,15,17
3 prime level runs at RG: 15,16,17
3 prime level runs at USO: 13,15,16
took 5-sets to beat him in 13,15,17 at AO (Djoko, Djoko, Fed). no easy enough wins for anyone or demolitions.
only 4 set in RG 16 semi and got demolished in RG 17 final
got demolished in USO 15 semi