Speaking of pigz, I've run into pigzpp[1], or rather its paper: "pigzpp: Fast, Parallel, Portable Compression for the Whole Stack"[2].

Turns out we can squeeze quite a bit more compression performance out of DEFLATE - ~10x in certain instances, 2x as a base minimum (read the paper for details).

[1]: https://github.com/thammegowda/pigzpp

[2]: https://arxiv.org/abs/2608.24153