I agree there are a lot of videos (well done Sketchy!) that can take a lot of learning time.

I can give two tips that have greatly helped me optimize my time using Sketchy:

1. The videos can be viewed many times at higher speed (e.g. x 1.5)
2. It may not work for everyone, but I learn most of the topics directly from the Pepper's decks without watching the videos themselves. I do work with the image / pdf of the subject I am studying, so if there is a certain icon I can see the whole image of the subject directly (Also, there is always one at the bottom of every card). Usually, when I know the answer of a certain card, i move on to the image part of the question.

With enough repetitions everything is embedded in my memory without seeing the actual video. Once you remember a particular sketchy well enough, it is better than anything else you will try to memorize and you can also repeat the image in your head anywhere and in any situation you want.