Not for my use case, but maybe someone here has a solution. I watch lectures and lessons, as I watch I will change the playback speed constantly. I use a Firefox add-on for keyboard control of the YouTube video stream speed.
VLC also has keyboard control of the playback speed. However, when changing the speed VLC will skip a split second of audio. This drawback negates all the benefits of playing faster over the non-essential parts, because when we get to an essential part I'll lose some if it. This is on Kubuntu, across many versions over the years.
I haven't run into that myself, but I think I'd just hit shift+left arrow (or just left arrow depending on what you've got the jump set to) before hitting + to speed the video back up. I'll take a minor inconvenience like pressing an extra key for all the other features I get.
You can probably also create a single macro to do both actions with a single keypress although not with VLC alone which is fair enough since you're using an addon for the functionality you can't get with youtube's player already.
VLC also has keyboard control of the playback speed. However, when changing the speed VLC will skip a split second of audio. This drawback negates all the benefits of playing faster over the non-essential parts, because when we get to an essential part I'll lose some if it. This is on Kubuntu, across many versions over the years.