I agree, MKX doesn't have any and I found that jarring. They are supposed to move after all. Btw, I don't use OMG mode anymore. I find the LR setting much more advanced and fitting
Slight correction @Lulu breast movement undulates, they do not bounce (even when it appears they do! ^_^
Observe as Sofia Vergara stirs her chocolate milk: https://www.youtube.com/watch?v=YPBYnz_RJiQ
It would be pretty weird and shanefull because they would obviously be for the sake of titillating.
In all honesty the realistic physics lends TN some integrity since big boobs are suppose to bounce around. They are just trying to keep it real.