What is the purpose of the .note section? If it is left out, it appears from ktrace that the kernel assumes the binary uses some other ABI, e.g., Linux, etc. (compat_linux, etc.) and the /emul shadow directory gets searched.
From the document: "OpenBSD native executables usually contain a .note.openbsd.ident section to identify themselves, for the kernel to bypass any compatibility ELF binary emulation tests when loading the file"