I made this topic for those who still haven't checked this out.
Today I tried syncronizing spine animations to music tempo, to 1 second beats to be exact, as a test. I noticed that even though spine runs at 60fps, 30 frames of the timeline are one actual second.
If I'm not wrong and everything is working right, spine refreshes the bone positions at 30fps but the movement interpolation is seen at 60 fps. For those who want to sync their animations to stuff keep this in mind.
Also, if this is a bug or can be changed in some way discuss it this post.