So it became vividly clear that previous metal progression system with only 3 tiers (soft metals, bronze and iron) were replaced with 5 tiers progression system(soft metals, bronze, cast iron, wrought iron, steel), opening wrought iron since L4 minehole, and steel since L5 minehole.
Considering in progression there's so called "cast iron age", I wanted to highligh that's it's quite empty of content, as there are exactly 3 new things you can do with cast iron, finding it on L3: Windmill, Volva's wand and Cast Iron Trivet.
For "wrought iron age", there is little more unique items being available Butcher's Cleaver, Chainmail Shirt, Druid's Helm, Fyrdsman's Sword, Hirdsman's Helmet, Winged Helmet
In my opinion, there was not enough content to split progression into multiple, so I wanted to say it's bad.