Hey @HidyBush! No, YouTube does not reliably include spoken word/transcript matches in search results. I've run tests where I open up the transcript of a video using these steps (https://kb.swtc.edu/page.php?id=90230), copy a few of the words, then perform a search using those words across that channel, and the video I copied them from doesn't appear on the list of results.

That's why VideoMentions Search exists. It provides a way to search the videos within a YouTube channel to reliably find spoken word matches (and it includes matches in the title & description, too).

Thanks for checking out my project! Please let me know if I can answer any questions about it.