Hi @tande, you are correct that if you are using the XR SDK in an academic setting then there are several licencing models that in your case would be the ‘research licence’
You can apply for a quote and more information about this @ https://vr.tobii.com/sdk/licenses/
Bear in mind however that if you use the HTC’s own SDK (https://developer-express.vive.com/resources/vive-sense/eye-and-facial-tracking-sdk/) then you are not obliged to follow our licencing model, so something to consider if budget is a problem.