I will agree that it's dubious that that nuance is reflected in the rulings on the Masterpiece case. I'm trying to follow the same lines set there, though, in my argumentation.
Would the added features be useful in another context? Would they be useful regardless of the type of work being done? Are they merely enhancements of the platform, or are they specifically tailored to the client's domain?
So if ICE asks github to prioritize better native CI support for Windows, or something, they're doing it because it is of maximum benefit to ICE.