While you can create and build a local package with U+FE0E in its file name, you cannot create or download a module using that character in a file name. So you could run this attack in someone's top-level repo but not in any of their dependencies. That's something at least.
People who clone a project and compile it manually get different output than people who `go install` it?
Is that inconsistency something that … should be fixed? Seems like it should be.