I'm admittedly not as knowledgeable about it as I'd like, but I also have a similar system. A primary encrypted Linux partition wuth a dualboot into Windows for times I absolutely need to go into it (which admittedly has been coming up less and less).

What I tell myself is that, sure, in the best case that everything works as I'd like, the rootkit can never bleed into the Linux side of stuff, and I'm really only ever at risk when I'm actively on the Windows, and even then if Riot remains a good citizen, nothing will happen. It's an (increasingly) small window of vulnerability.

Thing is, I've seen complete systems go down because of "small windows of vulnerabilities" before. Catastrophic failures, more times than I'd have liked. Who knows, maybe someday someone manages to exploit that window and use it to, for example, piggyback into your home network and access your devices. I dunno, call me paranoid.

In my head, installing something like a kernel anticheat is really not worth it. It's a huge over reach of privilege for so little gain for the user. And frankly, I don't trust Riot to be a good citizen with that much privilege on my machine.