Thanks for putting this tool together. I got to playing around with the icon and ended up creating a simple toggle svg that you're welcome to use. I would have submitted a pull request but those are disabled for the repository.
Code:
<rect width="22" height="8" x="1" y="3.5" rx="4" fill="#111827"/><circle cx="19" cy="7.5" r="2.5" stroke="white" fill="white"/><rect width="22" height="8" x="1" y="14.5" rx="4"/><circle cx="5" cy="18.5" r="2.5" fill="#111827"/>