react-navigation: selection of different routes based on whether the user is logged in or out, via redux

Main.js

import {rootNavigatorSelector} from './navigation/router';
import Store from './redux/store';

// Connect `rootNavigatorSelector` to redux.
const ConnectedMain = connect(state => ({
  Layout: rootNavigatorSelector(state),
}))(Main);

// App root component
class Root extends PureComponent {
  render() {
    return (
      <Provider store={Store}>   
        <ConnectedMain />
      </Provider>
    );
  }
}

router.js

import {createSelector} from 'reselect';
import {selectorIsUserLoggedIn} from '../redux/module/user';

export const rootNavigatorSelector = createSelector(
  selectorIsUserLoggedIn, // reselect selector that returns true if user is logged in
  signedIn => {
    return StackNavigator(
      {
        SignedIn: { // initial route IF signed in (see below)
          screen: Home, // home is a screen with no navigation header - when user selects an option from home, we go to a sub-route of MainNavigator (which has a header), below.
          navigationOptions: {
            gesturesEnabled: false,
          },
        },
        SignedOut: { // initial route if signed out
          screen: Login,
          navigationOptions: {
            gesturesEnabled: false,
          },
        },
        MainNavigator: {
          screen: MainNavigator,
        },
      },
      {
        headerMode: 'none',
        mode: 'modal',
        initialRouteName: signedIn ? 'SignedIn' : 'SignedOut',
      }
    );
  }
);