I'm confused. By Spaces animation, are we talking about the horizontal sliding transition?
On my machine (High Sierra) the transition time between Spaces is dependent on the finger gesture swipe velocity. I'm not really sure I would even call this an animation- the Spaces x-offset is being adjusted as I move my fingers along the track pad in the same way as scrolling up/down in a browser behaves. There's literally no waiting for the "animation" to complete; when I lift my fingers I'm either in one space or the other.
On my machine (High Sierra) the transition time between Spaces is dependent on the finger gesture swipe velocity. I'm not really sure I would even call this an animation- the Spaces x-offset is being adjusted as I move my fingers along the track pad in the same way as scrolling up/down in a browser behaves. There's literally no waiting for the "animation" to complete; when I lift my fingers I'm either in one space or the other.