springConfig = key => {
  switch (key) {
    case 'foldCenteringTranslate': {
      return {
        tension: 66,
        friction: 20,
      };
    }
    case 'transitTranslate': {
      return {
        tension: 95,
        friction: 25,
      };
    }
    case 'transitOpacity': {
      return {
        tension: 170,
        friction: 22,
      };
    }
    default: {
      return config.default;
    }
  }
}
NOTE: This code duplicates a lot of <Modal />.

It's 100% possible that this code can be reconciled and combiled, but it's
non-trivial (for one thing, it would be hard to imagine it without nested
ReactMotion instances, and that could be bad for perf).