There were a ton of different design variations! The differences were mostly in the details. The main requirement was to build a video editor that does everything that a video editor does, but as well as possible. And because this editor is designed to work within third-party apps that license the SDK, we wanted it to be well-designed but neutral, as easy to use as possible.
One example of a rejected idea: We had played around with the idea of collapsing and expanding the clips when you scroll vertically in the timeline, like an accordion, but it turned out that traditional vertical iOS-native scrolling felt better.