It sounds like even then, you'd have to agree to (or read) an EULA to know that this is some magical thing. It is certainly possible to implement something without ever doing either.
It's soft; like a lot of legal concepts, there isn't a black and white test.
At the end of the day it's what can be proven to a jury.
In this case for instance, I don't think there's a decent legal strategy for Yuzu wrt "we didn't know the encryption on switch ROMs was a 1201 protected device".
