Here's a link to a Fediverse post that shows the best way I've found to highlight text in the DOM. I got the inspiration from this Youtube video (below) as I was learning how to write Chrome Plugins, and was extremely happy with this solution.

My app uses it to highlight search results after someone searches the database for some text.

Here's the link...

Highlighting Text in DOM

Let me know what ya'll think!

Here's the Youtube that was the inspiration for this:

https://www.youtube.com/watch?v=rymG9UmPuhM