I don't know - but given Facebook's past with WebView on their flagship app I feel they would be best qualified to say whether or not those solutions once fully

I don't know - but given Facebook's past with WebView on their flagship app I feel they would be best qualified to say whether or not those solutions once fully implemented are satisfactory. It could be the case that the features you mentioned are suitable today for web applications targeting the latest iPhone on browsers on the latest standards, but not when React was first developed.