in react-navigation@^2.16.0 you can opt into this with stack navigator and bottom tab navigator:

```

import { useScreens } from 'react-native-screens';

useScreens();

```

drawer does not currently render more than a screen at a time so it doesn't matter, but i will be changing that shortly and adding support for react-native-screens there as well. see https://www.youtube.com/watch?v=Z0Jl1KCWiag for more information about react-native-screens. see https://twitter.com/janicduplessis/status/1039979591815897088 for an example of memory usage improvements.