Well, this seems pretty useful. Certainly worked well when I tested it on the Web Tiger Team site.

However, I do wonder whether the RSS feed aspect might be limiting here. I mean, how often do people manually generate an RSS feed on a static website?

I'd say the answer is 'pretty much never'. They're annoying to create/edit by hand or with a static site builder, and hence they're usually quite rare on the types of websites this tool was made for.

So while I think the widget works well when used properly, I feel like the vast majority of static sites won't be able to use it simply because they don't have an RSS feed.