Try the head physics setting in rF1 and you will see it does exactly the same thing as in rF2. It doesn't lock your view to horizon, it balances it subtly. With both head physics and exaggerate yaw you'll notice a more obvious effect.
I will go back and try again. Head Physics=0, Head Physics=0.5 and Head Physics=1.0 all looked the same to me. In AMS, you get the wildly different results that are expected from adjusting that line, with no use of Exaggerate Yaw. EDIT: My mistake. I see now that rF2 Head Physics does have a very small effect--about 1/10th or 1/20th of the same setting in AMS. So no ability to replicate the g-force based (not controller-based) head physics of AMS in rF2 (that has nothing to do with yaw or vibrations).