Streamproof
This guide shows you how to stream with GM Cheems running without the analysis showing up on stream.
The trick: hide the on-page overlay, then read the analysis from GM Cheems' DevTools panel in an undocked window. OBS captures only the stream window, so the undocked panel never appears on stream.
Step 1 - Use Window Capture on OBS
Use only one window and use Window Capture on OBS to stream it. This window will be referred to as the Stream Window.

Step 2 - Hide the GM Cheems Overlay
Open the GM Cheems settings page: click the hamburger menu at the top of the sidebar and choose Settings, or click the GM Cheems extension icon in the toolbar.
In the Streamproof section, uncheck "Show GM Cheems Overlay in web page".
Now, the GM Cheems sidebar and arrows will no longer be shown inside the web page, for all tabs.

Close the settings page and go back to the Stream Window.
Step 3 - Open Developer Tools
In the Stream Window, open the DevTools by pressing F12 or click Chrome Menu > More Tools > Developer Tools

As you can see, the DevTools will show up in OBS, which leads us to the next step.
Step 4 - Undock the Developer Tools
Click the "Undock into separate window" option in the DevTools.

Now, if you look back at OBS, DevTools should not show up.
Step 5 - Open the GM Cheems tab in the DevTools
The GM Cheems tab will usually be located at the end of the DevTools tabs.

If you don't see it, it's probably hidden in the "Extra Tabs" menu

Step 6 - Prosper
You now have a solid Streamproof setup! 🎉
If you have multiple monitors, you can have your Stream Window on one screen and DevTools on the other.

Preventing Leaks
Do not pin the GM Cheems icon
This might be obvious, but don't pin the extension icon in the toolbar, otherwise it'll show up in OBS.

Never use Screen Capture
Only use Window Capture, to prevent other windows from showing up on stream.
Don't open Settings from DevTools
Opening Settings from the DevTools will cause the GM Cheems settings page to show up in the Stream Window.
Instead, open another Chrome window, one that doesn't show up on OBS, and click the GM Cheems extension toolbar icon to get to the settings page.
2 monitors 1 Webcam
If you're using two screens and you have your webcam on, don't put DevTools on the 2nd monitor.
People will see that you are glancing over to your other monitor.