Great question! This is a much requested feature that we have seen interest in for our course video content. Currently, the player that we utilize for our course video content -- the Vimeo Video Player -- does not support this functionality.
As such, our videos do not have the ability to increase or decrease the speed at which the video is played.
However, we do have written confirmation from Vimeo that this feature is on their product roadmap and well on the way. In addition, we are looking at all possible alternatives to bring this feature in for our students as soon as possible.
Thus, be on the lookout for this feature in the near future! If there are any other comments, suggestions, or recommendations you'd like to provide, feel free to submit them in a Help Center ticket.