Alternative compression method to reduce the download size?

[Unknown78]

For example: Thorium_AVX_121.0.6167.204.zip
I've noticed that the compression method is mostly deflate

Why not ultra lzma2 in .7z format for better compression ratio?
I've got it down to 156 MiB instead of 256 MiB.

It saves network data usage and may also download storage or nand write cycle if that matters.