I do think it would be cool though to expand SponsorBlock into more crowd-sourced things, since there is already a community of people willing to help.
Unfortunately this one seems to just change the casing of the title and then grabs a frame from the video to use for the thumbnail. I find that the thumbnail at least sometimes contains something useful whereas this may be counterproductive.
With YouTube you can hover over the video thumbnail and see a short preview of the video play so that aspect is already kinda covered by YouTube itself.
It's definitely getting closer to what I was talking about but unfortunately falls short.
I do think it would be cool though to expand SponsorBlock into more crowd-sourced things, since there is already a community of people willing to help.