Check out GitHub - divnix/digga: A flake utility library to craft shell-, home-, and hosts- environments. which seems very promising foundations.
ref: GitHub - DavHau/nix-portable: Nix - Static, Permissionless, Installation-free, Pre-configured
More discussion: Nix Portable: Nix - Static, Permissionless, Install-free, Pre-configured
Since it’s Google, it might be a fitting cabdidate to revamp k8s support from a nix perspective. Projects like GitHub - xtruder/kubenix: Replaced by https://github.com/hall/kubenix lay a good foundation. That would also play well the other way round, e.g. a kustomize plugin to render from nix-lang / kubenix config.