Yep, that did it, thanks.
For any Mac users wondering, if you double-click the chrome-capture-for-channels-macos-arm64 you will see this dialog:
However if you hold down the control key while double-clicking (or control-click and choose "open" from the contextual menu) you will see this:
Click "Open" and that's it. Another way to handle this is under System Settings > Privacy & Security:
I didn't have to change anything in System Settings > Privacy & Security > Screen Recording or anything else like that. I'm now up and running with Weatherstation streaming. Very easy. Now I'lll go in and set up the custom channels I set up previously for web pages like Home Assistant. And a bunch more! I'm going to set up some channels I'd set up via HDMI and see how the experiences compare.
This is awesome. Thanks everybody! What a fun team effort!