Just a few idle thoughts from my time playing and tweaking this mod. Others may not share my opinions, of course.
The ability to directly forge metal armor would be nice. It didn't make much sense to me why I had to make a non-metal version, then reinforce it. Especially in the case of gauntlets, under which players are generally wearing a pair of gloves anyways.
There are a lot of low-tier items in the crafting list that I just can't see myself ever making. Stone and bone tools sound cool, but serve no purpose once you find even a slight bit of metal. Maybe if megabeast bones had properties similar to adamantine or even steel, but otherwise I can't see myself ever making anything with them. That said, adorning the grip of my sword with dragon bone is pretty awesome.
Two step production of spears is a pain. Again, I'm never going to bother with stone/bone/wood spears, so maybe I just don't see the point and others care about it more.
Being able to resize clothes and armor sounded nice, but in practice it's better just to tear everything down to scrap and craft a ☼new version☼...
...Except that you can't craft many important types of clothes, like leather shirts, trousers, and more. If part of this mod's goal is to enable players to walk around in the skins of their defeated foes, this seems important. Especially for players who don't want to sacrifice their metal armor for bone.