"The method is suitable for headlines and a single short paragraph of text. It’s not suitable for long paragraphs of texts or multiple paragraphs. It yields no benefit over the browser’s default layout engine when the text exceeds a couple of lines. You’ll also end up with paragraphs of uneven widths, which breaks up the cohesion of the right-hand text edge of your design. It works great for two–four lines of text, though."

Knuth-Plass is for setting all text to a specified width and balancing as best as possible within that, not having varying widths.

It wasn’t really relevant in this context. It’s similar to what the browsers do by default, however.