Author of the post - I'm a big fan of technical solutions that feel boring and light weight. There sadly are a few interesting and wild types written to support this pattern, but I found them perfectly stable in real world applications. Once written they were set and served their purpose.
The main goal is to eliminate the need for as many tests as possible. I find that I hate writing tests but I love writing types. So the more heavy lifting I can get TypeScript to do the better.