It would be more upfront work, that’s for certain. But some of that work would be done by people anyway, as they do the full nixos-qubes enablement – so my guess is there’d be a potential for collaboration. Once that’s done, though, I would say Nix as a language is far superior substrate for this kind of affair than salt or similar.
More to the point of liteqube itself – another benefit would be the fact that on NixOS we can trim packages rather easily, by disabling unneeded functionality and therefore trimming the library dependencies – which would be impossible without introducing alternate builds for .deb/.rpm packages.