Looks like you are getting 99% rejection, thats amazing. I only get 96.5-97% rejection.
Are you using membrane from BRS?
I bought the water saver kit from BRS, but the first membrane is a Dow membrane I bought somewhere else. I calculated it @ 98.8% rejection which is amazing I agree. I have great water pressure though, 85psi in front of the membrane with no booster.