The CVT is essentially magnetic when it comes down to it. Our rav4 is a 4 cylinder with the same principle of transmission - the driveline is /fun/, though in RAV4 guise it’s noisy and has a little thrash to it over 2400 rpms or so. At 70 however there’s no engine noise at all, and it’s probably lugging away at a very dampened 1300 rpm. My guess is driveline vibes in the RX will be imperceptible. Also, that suv weighs around 4700, which dampens a lot of vibrations.