I actually wrote a script which creates a trampoline launcher for this. It has its flaws but it solves the spotlight issue, and supports pinning to Dock across updates.
This is great! I run a script with mkalias[1] which works fine but all icons have this ugly arrow. Yours works perfectly - only thing missing is the icon in the spotlight search.
Available as a plug-and-play module for nix-darwin and home-manager: https://github.com/hraban/mac-app-util