I made some phone calls to Praxis, Rotor, Shimano, here is what I got.
From Praxis works, the 50/36 may eliminate the rub, they will exchange the rings if I want to, the Shimano teeth of the outer ring is farther away from the inner ring is true, and they are looking into it right now, may come out with a new version.
From Rotor, the preload cap on the none drive side should completely tread in, mine is not all the way in.
From Shimano, other than the alignment of teeth, the Shimano outer rings have some kinda black coating, the coating will take out the noise if the chain is very close to the inside of the outer ring.
I took off the spacers on the BB, made sure the preload cap is all the way in, I didn't use the chainring washers.
I am going to stay with the setup, it was only minor rubbing from the 2 smallest cogs, I don't use these combo anyway.
Have I had a chance to start over again, I would keep the DA 7950 for sure, by the way, my bike is BMC SL01 54 Ultegra Di2.