Accessing iframe context with Electron

I have an Electron app where I load external sites into a BrowswerView hosted in a BrowserWindow. Invariably each site has a video player on it using a <video> tag. Normally you can access the DOM using executeJavaScript and do things like this:

document.querySelectorAll('video').forEach(input => { input.pause() })

This would pause all the playing video on the site.
Problem is, one particular pesky site loads the video player into an iframe that is in a different sub domain.

Enter CORS. I cannot get to the video container without hitting the dreaded Blocked a frame with origin "https://www.whatever.com" from accessing a cross-origin frame.

Here is my question: In the chrome dev tools you can select the context from a drop down so clearly it is possible to choose the context from the client. As I am running this in Electron I would like to believe that there is a way to switch contexts. I am not looking to run the code cross origin but directly in the frame I just need a way to choose it.

I looked at mainFrame.frames but I don’t see how you get to the sub frame’s webContents.

Any clues on this?