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.