If the game supports it. I can guarantee you that by Q3 2018 there still won't be even a handful of big titles supporting it. Most likely even 0. We need the big guys to jump in first. If Oculus or HTC bring out a headset with this feature THEN things will start to roll. Pimax is just way too small I'm afraid to move the industry. Sure some other smaller companies are now using eye tracking too like the Fove and Deepoon (if I understand correctly my E3 has it too). But still I highly doubt this will move developers.
Don't get me wrong, it's awesome that Pimax will support it ! But you make it seem like this is going to get us huge advantages right away. The only possible advantage for now is in the HMD rendering (and that's just a minor GPU gain compared to game rendering). And seeing how slow Pimax development is ... I doubt we'll even have that at launch.
Oh and something else, while eye tracking sounds extremely potent in theory, it yet has to be seen how well it works in practice, depending on the specific implementation. Latency is a huge thing when it comes to eye tracking, you will want the next frame to be 'in focus'. Also very important is accuracy. Like we now have all these problems with drift, I can see already similar problems with eye tracking where the game renders out of focus where you're actually looking at. If that happens too often, you won't use this feature anymore....
Sorry to be the party pooper here, LOL, but people's expectations need to be realistic otherwise it's going to be one big show of disappointed people after the kickstarter launch.
BTW I even doubt SteamVR supports eye tracking at the moment ? I'm googling but can't find anything about it at all. In fact I've just spent 15 minutes to find a single VR app that supports eye tracking (to test with my Deepoon E3) I haven't found anything at all ... Pretty sure SteamVR doesn't support eye tracking at the moment. So I have my E3 for several months already and can't use it at ALL for eye tracking. I'm sure it will be the same with the Pimax 8k. We'll have to hope that HTC supports it in their Vive 2, THEN steamVR will support it and then developers will start writing for it.