Sorry, I've been both a bit busy and sick the past few days.
Judging from your video, you seem to have an expectation that Spine animations play back when you scrub the Unity Animation window.
This is unfortunately not the case, as Unity doesn't provide the API to allow us to do that. And Spine Animations aren't converted into native Unity AnimationClip objects because Spine has many features that Unity Animation does not. Instead, The AnimationClip assets you see are dummy animation clips that simply match the duration and event names of the non-Unity-serialized C# Spine.Animation objects.
SkeletonAnimator is a workaround so that users can use a Mecanim state machine to control Spine.Animations at runtime.
