Greasy Fork

If I understand the intention of your script correctly, then you might wanna look at SponsorBlock.
It was received well and works greatly: https://sponsor.ajay.app/
HN discussions:
https://news.ycombinator.com/item?id=26886275
https://news.ycombinator.com/item?id=20778926

The author JustDaile replied on another duplicate thread https://greasyfork.org/en/scripts/463067-youtube-automatic-bs-skip-edited/discussions/176176#comment-380855

Blocking sponsored content isn't the point of this script.
Its point is to skip intro's and outro's that some creators fix to each of their videos.

I totally agree, I want to skip only those uninspired and embarrassingly badly produced intro clips of some of my fav creators. I do not want to skip any sponsored ads, I want to support the creators so I fear skipping them damage their income. In fact I am interested to see what they come up with coz ads could be lighthearted, funny and refreshing sometimes.

So in case you didn't know, you can customize SponsorBlock and pick which categories are skipped. So if you wanted you can actually not skip sponsors at all, but only skips intros/outros.
That being said, you have to either set the intro/outro per video yourself, or wait for other people to set the intro/outro for the video before you watch it.
This is why I love BS skip, I set the intro/outro for the entire channel, and it will skip the intro/outro for every video that channel.

This means I can even use sponsorblock in adjacent to BS Skip. I set the intro/outro skip per channel and then do the sponsors skip and take advamtage of both options.

<3