Efficiency compared to Make Tracks

Cons:

This option costs 7.5 more Bessemer Steel Ingots than making tracks regularly, 0.5 more BSI per Railway Steel, or about 2% less efficient in terms of BSI cost

Pros:

This option costs 0.75 less Justificande Coins than making tracks regularly, 0.05 less Justificande Coins per Railway Steel, or about 20% more efficient in terms of Justificande Since the action cost is identical to the Justificande cost, it also costs 0.75 less actions for 15 Railway Steel, 0.05 less actions per Railway Steel, or 20% more efficient in terms of action economy, at least for converting the railway steel.

Additionally‚ there is a one-time startup requirement of 500 Laboratory Research, 5 Bessemer Steel Ingots, and 250 Nevercold Brass Silver + a requirement of having upgraded your equipment to level 5, all to create the Infernal Machine this requires. Of course, you also need an additional worker, but you should already have if you spend any time in your lab, having 3 workers is the minimum to avoid getting really bad black-bordered cards when researching.