Ya I did go vertical in my last attempt, but I could only fit 24 smelters on the first floor and then got to tier 5 and unlocked more stuff which put me over the edge of needing more I needed to build a second factory or a new floor on top with more smelters and it just got super complicated for me, needing to send ore to two different spots and organizing the ingots going everywhere I needed. I also have a thing about organization, symmetry, and logic and I just could not find a “satisfactory” way to build it knowing once I unlocked a new tier, without knowing what I would need ahead of time, everything I built would probably need to be redone at some point again