[Feature]: WebResourceRequested, but just for the main frame and only when we're waiting on the first response

Describe the feature/enhancement you need

related to this issue I opened

In Electron, I'd intercept onBeforeSendHeaders and send back some response headers for the initial navigation.

In WebView2, I'm using WebResourceRequested.

I add a filter on the document:
coreWebView2.AddWebResourceRequestedFilter(url + "*", CoreWebView2WebResourceContext.Document);

I add the "*" because the site might be redirected/load-balanced somewhere else.

However, this handler fires for every navigation, even for iframes.

Is there anyway to only run this for the main frame?

Additionally, I would only set these response headers when isWaitingForResponse return true. Is there a similar concept in WebView2 land?

The scenario/use case where you would use this feature

on main frame navigations, send up some response headers

How important is this request to you?

Impactful. My app's user experience would be significantly compromised without it.

Suggested implementation

My current solution is OK, but the logic is just running way to frequently (on every iframe navigation). I want to run it once when navigating the first time.

What does your app do? Is there a pending deadline for this request?

No response