If a player were to silk touch a dense iron ore, for example, they cannot then smelt it into multiple ingots. The dense ore mechanic only accounts for multiple drops when mined without silk touch.

Mod version: 4.2

Thanks for pointing this out! I never really intended for things to work like that, but I can see how it would be an improvement and will look into it soon.

Hey, there. Sorry this took me so long to get to. Just letting you know that I have now implemented this feature and an update should be out later today.