Hi @jrgordon, apologies for the delay in response I’m afraid the HTC Vive Eye Pro is a product we no longer actively support and as the XR SDK is a free product, it is difficult to give priority to detailed questions of this type.
However, there is a means to interface directly to the eye-tracking data provider (in this case HTC), through the TobiiXR.Internal.Provider property. It might be possible to use that to update eye-tracking data faster than the application framerate by using:
var provider = TobiiXR.Internal.Provider as HTCProvider; provider?.Tick();
Although we cannot guarantee its efficacy. Should this method not work, then we would, unfortunately, recommend you use the SRanipal SDK to achieve 120Hz capture rate.