const Component = observer(function (props: IProps)) { /* Note that this is, in fact, an anonymous function */
    const { useHook } = props;
    const { myState } = useHook(); /* A hook cannot be used inside of another function */
    return <div>{myState}</div>
})

const WrappedComponent = function() {
    const [state, setState] = React.useState();
    React.useEffect((
        expensiveState.lazyImport().then(s => setState(s));
    ), []);
    
    const Wrapper = React.useCallback(() => state ? <Component {...state}>/> : <Loading/>, [state])
    return <Wrapper/>
}

ReactDOM.render(<WrappedComponent />, ...)