This is a theory that has been brewing in my head for some time, concerning Steel Compounders. While extremely powerful, an effective limit is placed in the form of air resistance. Thus, they cannot tap too much speed, lest they literally burn up.
While an interesting case study of Sanderson's Second Law of Magic, I have always found it to be frustrating. So, I started thinking of ways to circumvent this issue.
This is no novelty. Many have already conceptualized combining the [Stormlight Archive Spoiler]
with Steel Compounding, which would be an effective way of going about eliminating the issue.
However, such inter-planetary interaction isn't likely to occur for some time. So I started thinking of ways to make Steel Compounding safer using only things available on Scadrial.
This leads to my theory. Could a Steel Compounder take a brass medallion (or a brass spike) and begin storing heat? With the use of heat Feruchemy, all heat generated by the air resistance would be siphoned away, preventing any damage to the Compounder. With enough metalminds, no heat would linger long enough to pose any threat, allowing the Steelrunner to speed up.
Of course, the faster the Compounder goes, the more heat will be generated. This may eventually prove too much for the limited nature of Feruchemical storage. However, the Steelrunner would not be forced to last long. Eventually, they should be able to accelerate enough to break the sound barrier, thus ceasing the accumulation of heat.
This is how I think Steel Compounding can emerge even more powerful than before. What's worse, Hemalurgy isn't even necessary. Southern Scadrian medallions solve that problem quite beautifully. I do not know if this theory is sound, so feel free to comment below with any corrections or counterarguments.
~Longshot97