This is a popular request and we would like to add it, however it is also a rather large task and we won’t be able to work on it in the nearest future.
For now, you could try to incorporate a minmap using JavaScript API and custom HTML for UI, but it would be rather a larger undertaking. A minimap images would need to be produced manually, for example based on an orthographic top view from SketchUp. With the JavaScript API you can do something like this: 3D scene but you would need to extend it to use a map image instead of a gray background and add some HTML UI elements for folding such map.