Also here is a page with the features explained which you can use in combination with a motion sensor: Device state automations (smart switches, motion sensors, lights, and plugs)
To answer your question, scene fading is not currently supported. However, I am currently working on that and already have it working here. I expect to update the app with that feature within a few weeks (it will be called “Automations”). If you would like to try this feature out earlier please let me know and I can add you to a testing group.