Principle Feature Request

When I first found out about Principle it changed the game for me, not an understatement. Thank you for saving me so much time and effort, @Daniel Hooper

Principle is my go-to app when it comes to animating UI. I adore its simplicity and quite frankly functionality. The volume of what you can do for the time in this app given you only start with just a rectangle is astonishing. There's just this one little teeny tiny but so important thing. Just one thing that still makes me go to AE or Flinto sometimes. 3D rotation.

What if there were two co-dependent angle controls that would add so so much value to this beautiful app.

I know there's adjacencies like should the depth be adjustable too or should the back side be customizable. For me personally that doesn't require any extra controls:

- The default depth is fine given the average distance (informed by this study) people keep between their eyes and smartphones. Only in rare cases (likely unrelated to UI animation) would someone have to change it.
- The back side of an object could just basically be another object that has the same rotation values in the transition.

Anyways, just venting here. Let me know if you guys think that might help you too.