nix-daemon and per-user proxy settings

I've just installed nix to use on macOS. I have a proxy set up with appropriate *_proxy environment variables in my user environment, but of course nix-daemon isn't run as my user.

I could try and add the proxy variables to the generated org.nixos.nix-daemon.plist, but would prefer not to because if I take my laptop home and thus don't need to use the corporate proxy then I have to stop the daemon, edit the .plist file to remove those settings then re-start the daemon.

As such, is there any way to have the daemon use my user's proxy settings (or lack thereof)?