Perhaps 1.5x is too much (as in the example above), but I think 1.33x speedup would not be noticeable. People just think I drank a lot of coffee and talk fast.
If YouTube player had more speed options keyboard shortcuts like https://chrome.google.com/webstore/detail/video-speed-contro... then I probably wouldn't touch the source.
* If the instructions are worth making, more time will be spent viewing them than producing them.
I try to get the whole video in one take to save editing but I'll do multiple takes to try to get it right/succinct. I consider the first one a draft/rehearsal (though if it works out, great!).
This still doesn't take very long (even when using a small area of the screen to save file size), and viewers should find it easy to pause or back up a few seconds.
This is all for step by step style instructions rather than heavy conceptual teaching, though.
Also, for documentation it sometimes works even better to make a looping, animated GIF of a single step and then inline that with a text description.