I would like to request linux support as well.
As for the linux capabilities of the Tobii XR SDK, I received an answer from Tobii customer support that states that the Tobii XR SDK is build on-top of HTC's SDK and that they cannot offer linux support as HTC is not supporting linux. So far I assumed that HTC is using Tobii software for the eye tracking and therefore the dependency was the other way around. But now I am very confused which software depends on which here and where the actual bottleneck is.