I think I have finally ran into the issue last night while running with my SO healer; it never seemed to happen during any dungeons, but it did during a few fates. Mind you I didn't have defiance up, but she never use to surpass 60% of my hate output running SE > BB and she was riding my ass through the whole fight, haha.

I don't think the problem comes from the tank stance hate multiplier if I can view a sizable difference w/o defiance up though. Either way, I didn't see any patch notes regarding combo hate multipliers, so does that mean the infamous spaghetti coding SE is known for plagues FFXIV too? Haha