there is no perfect solution.
you can do a custom handler to access the native events and use webView:didFinishNavigation to know navigation completed. if the page has dynamic content, you may need a timer to track changes. see this thread:
https://learn.microsoft.com/en-us/answers/questions/1530234/custom-webview-renderer-in-maui-ios
iOS webkit:
https://developer.apple.com/documentation/webkit?language=objc