Sadly, the authors hard coded the expected headers so it’s not fully gzip compatible (you can’t add your own arbitrary headers). For example, I wanted to add a chunk hash and optional encryption by adding my own header elements. But as the original tooling all expects a fixed header, it can’t be done in the existing format.

But overall it is easily indexed and makes reading compressed data pretty easy.

So, there you go - a practical use for a gzip party trick!