Opinions on Highlighter for Safari

Does anyone have experience using the Safari extension Highlighter for Safari? I’ve searched high and low on blogs and YouTubes and can’t find any real reviews of it other than briefly being listed in a useful tools round up and I got the impression that the YouTuber had not really used it.

It is number 13 on the list of paid apps however the reviews on the extension are limited and a mixed back. As unfortunately, Raindrop.io doesn’t allow you to annotate web pages and I prefer this tool in every other way to Diigo (and I can’t afford to pay for both subscriptions) this extension seems like the perfect solution but I am looking for some trusted opinions before jumping in.