Previously worlds in Isomer were generated using one ruleset depending on the type of world i.e. Temperate, Frozen or Desert. The entire world would have this single ruleset and therefore type of blocks throughout.
During a bit of experimenting with unrelated code, I started generated worlds comprised of different zones or biomes. Currently this is very experimental, I like the added variation to the worlds but I'm not sure if this should be kept or developed further. Let me know what you think!
A few screenshots from the experimental world generation tweak: