I’ve been running Sway with NixOS for a few years now, with Home-Manager for probably the majority of that. However, a basic setup is more or less just enabling the relevant home-manager option for Sway.
So my configuration is going to mostly be my own customizations, or example usage of how I pull in sway-tip from nixpkgs-wayland, which may or may not be appropriate for you given your taste for ecosystem breakage (for example, some Rust apps that haven’t taken a recent smithay-client-toolkit patch don’t work on sway-tip or Plasma 6).