The effects you can make with this are fantastic. My only issue is that if you skip scenes (eg go from Scene 1 to Scene 3 in the example shown in the description) things jumps around, and I can't work out a way to get around this.
Edit (well delete and new review...) -- I worked out how to do it with many extra scenes for each transition. Originally I had just 4 scenes (fullscreen 1, fullscreen 2, 2 picture-in-picture 1, 1 PiP 2) but to get the transitions I've ended up with 10 scenes!
https://i.imgur.com/ecISKwB.png