I just got final v29 Oculus desktop app today. First time in a while all my Oculus headset are in sync, lol!
I found that all I needed to do to get 120Hz option to show up in the Q2 device quality settings was to get out of Air Link, shutdown the Oculus desktop app, go to the Q2 experimental settings, and enable 120Hz. Then when I restarted the Oculus Desktop app, enabled Air Link and reconnected it, the 120Hz option re-appeared. Easy peezy imho.
Otherwise, v29 seems to work fine with both my Q1 (unfortunately no Air Link option yet, or higher refresh rates) and my Q2.
Edit; hard to believe there is not an official v29 PC final thread out there yet!