5P steady state and special cased first input.

The first product and product 4+5k use seven inputs, projecting straight from lead. All other products use six inputs, projecting from iron. This uses a lead worth of additional metal. The 7 input products provide an iron for this purpose, that gets slowly used up over the next 4 products.

At various points while working on this solution I used omclone, FTSIGCTU, merge tool and F43dit. So shoutout to the developers.