One thing the mod currently lacks compared to vanilla is that it does not yield any experience for smelting ores through the bloomery!

For example, smelting Iron Ore in a vanilla furnace normally yields 0.7 XP per ingot smelted. The bloomery never appears to award xp at any point.

The xp could be awarded when you remove the bloom for the first time, or it could pop out while you hammer away at the bloom. (The latter might feel more stratifying)

Perhaps look into into adding some xp drops to other mechanics as well, such as Pit Burning for charcoal.