From what I’ve found when I got my dock only the official dock supports VRR on HDMI, something to do with display port over USB-C converting to HDMI, I have the Jsaux 12 RGB dock and threw HDMI no VRR but if I hook it to a monitor with Display Port VRR does work. So if you’re hooking it to a TV then your only option is the official dock for VRR.
From what I’ve found when I got my dock only the official dock supports VRR on HDMI, something to do with display port over USB-C converting to HDMI, I have the Jsaux 12 RGB dock and threw HDMI no VRR but if I hook it to a monitor with Display Port VRR does work. So if you’re hooking it to a TV then your only option is the official dock for VRR.