why not just check the path? C:\Program Files (x86)\Microsoft\EdgeWebView\Application

seems a lot easier than checking the reg. important if you are doing a silent install: MicrosoftEdgeWebview2Setup.exe /silent /install

you need check in a loop with a 2 sec pause if the path exists before starting up the app.

https://developer.microsoft.com/en-us/microsoft-edge/webview2

its the evergreen standalone installer