I tried exactly that. Turns out it can't be a .bat or .ps1 for understandable reasons, it has to be an executable. So, my "default browser" on this machine I'm

I tried exactly that. Turns out it can't be a .bat or .ps1 for understandable reasons, it has to be an executable. So, my "default browser" on this machine I'm on is now an .exe that prints $1. It works.