@mischievoustomato@RustyCrab@Zergling_man@creamqueen i know dwarfs does an even more aggressive job; it does nilsimsa similarity hashing on blocks, so it sorts all of the blocks on the filesystem by how similar they are which then allows the zstd pass to be more aggressive.
but that's a thing made by a madman designed to store 200 perl installs. it's not something you can readily ship a game on.