Problems with full screen rendering

I can't get ModalBox to work properly. I want to have a bottom oriented Modal where the rest of the screen has a semi transparent backdrop. Kind of default. What I'm seeing is a transparent overlay and no backdrop. I'm not too familiar with this component. But it seems like the height is set to the enclosing component and the positioning set relative to that instead of to the entire screen. (the height parameter looks suspicious)

I apply it in a deeply nested structure.

I'm using RN 0.32. Any suggestions?

<Modal
    isOpen={this.state.pickerVisible}
    position="bottom"
    style={{backgroundColor:'white'}}
    >
      {this.picker(field)}
  </Modal>;

Start by reproducing the nested Modal example on React Native 0.32 and inspect how ModalBox calculates full-screen height, positioning, and the backdrop. Done means a bottom-oriented modal has a semi-transparent backdrop covering the entire screen, including when rendered in a deeply nested structure.