Well, I assume your driver runs in kernel mode, because it start with the system. You straight away render most user mode cheats useless, the basic ones at least, where they are flagged instantly. At the same time 'someone more skilled' can find a vulnerability in your code and run their code in kernel mode. There is no way you can guarantee this won't happen, even when You state that several security teams had a look at your code.
There were multiple examples over the years with kernel drivers being exploited in the wild, Razer Synapse, Capcom and I believe there are several ways to break FaceIt anticheat.
You also stated it's very simple part that runs in kernel mode, which worries me that it will be simple to disable / override and render useless. Secondly, do you inform us anywhere during installation about this technique? I have beta access, but of course I skip all the reading and honestly don't remember.
While I can't guarantee that we're perfect we have put a lot of effort into the security of the kernel driver. We've had multiple groups review it for security flaws (both external security consultancies and our own security teams).
We definitely don't want to put yet another vulnerable driver out into the world!