raw ash is the one resource I never run out of…ever. It’s like leather…gotta throw some of it away. EL its a useful biproduct of gold farming (unlike obsidan which just weighs you down) and as others have said, there are hundreds in chest in the vaults.
However I see your point. It could be a biproduct if you use wood or dried wood in the furnaces. Give it some point to use that instead of coal.