Thank you for using Syncfusion products.
Animation speed in DockingManager can be modified using the attached property AnimationDelay. We would suggest you to set very short(might be zero) timespan for AnimationDelay property so that it will look like autohide window pop into place instead of animating into place. We have prepared a sample for the same please download it from the following location,
Please let us know if you need further assistance on this.