Both Smelter and Foundry are going to have a Mk2 version and, if I'm not mistaken, those are going to be just the same models working faster (up to 50%).
I was thinking about something past that point without having a redundant Mk3, look alike, version : which would be a Blast Furnace.
Quite huge building having the feed hatch on the top and a couple of ground level outputs. This new machine would work as both Smelter and Foundry simultaneously, even with one single merged input. The strong point of this building would be a bigger internal buffer to compensate the input feed without lacking efficiency, matched with an output rate slightly better then Mk2 counterparts. Also this may "spice up" the variety of looks and production approach in our factories.
Does it sound viable?