Same as https://github.com/facebook/react/issues/10103, but for the server renderer. You can look at implementation in https://github.com/facebook/react/pull/11168 and do something very similar in `ReactPartialRenderer.js`.
return <g>{props.children}</g>;
    }
    expect(() =>
      ReactDOMServer.renderToStaticMarkup(
        <div>
          <inPUT />
          <svg>
            <CompositeG>
              <linearGradient />
              <foreignObject>
                {}
                <iFrame />
              </foreignObject>
            </CompositeG>
          </svg>
        </div>,
      ),
    ).toWarnDev([
      'Warning: <inPUT /> is using uppercase HTML. Always use lowercase ' +
        'HTML tags in React.',
      
      'Warning: <iFrame /> is using uppercase HTML. Always use lowercase ' +
        'HTML tags in React.',
    ]);
  });