I apologize if this suggestion is superfluous, but I honestly haven't seen one already inclusive of it.
Here it is: with the addition of mithril mail, almost all mithril armour now uses mithril mail in the recipe which is more cost effective, with the exception of horse armour. Perhaps could the recipe for horse armour also be updated to use mithril mail instead of ingots? It is right now worth 14 mithril mail (7 ingots), and I think it would be great if it was more matched to other armour and use 7 mail instead. Thanks!