nix2container: Layers contains duplicate dependencies

When using layers results in layers containing multiple identical packages Example:

{
  inputs.nix2container.url = "github:nlewo/nix2container";
  inputs.nixpkgs.follows = "nix2container/nixpkgs";

  outputs = { self, nixpkgs, nix2container }:
    let
      pkgs = import nixpkgs { system = "x86_64-linux"; };
      n2c = nix2container.packages.x86_64-linux.nix2container;
    in
    {
      packages.x86_64-linux.default = n2c.buildImage {
        maxLayers = 100;
        name = "hello";
        config = {
          entrypoint = [ "${pkgs.hello}/bin/hello" ];
        };
        layers = [
          (n2c.buildLayer {
            deps = [ pkgs.bash ];
          })
          (n2c.buildLayer {
            deps = [ pkgs.zsh ];
          })
        ];
      };
    };
}

Result: glibc (and few other deps) exist in both bash and zsh layers

I noticed there is ignore option but seems to accept only a single store path. Is there a way to deduplicate derivations?