I am unable to create a steel plate, I popped a stack of wrought iron in there and I am unable to switch to that from an iron casting. Am I missing something?

Nothing missing. Its just a bug, which is reported in the forum, too. The problem occurs, cause the recipes for furnaces are limited by the input. Please consider, that this mod is in a very early stage and with that complexity, there will be more issues.

Understood, thank you.

The steel plate and more will be fixed for 1.1.0 out shortly, thank you for bearing with me through all these bugs.