Alfred Agrell (@Alcaro) commented about dlls/ntdll/unix/system.c:
&boot_info.BootIdentifier.Data4[3], &boot_info.BootIdentifier.Data4[4],&boot_info.BootIdentifier.Data4[5], &boot_info.BootIdentifier.Data4[6],&boot_info.BootIdentifier.Data4[7]) != 11)goto try_read_hostid;}else{try_read_hostid:+#endif +#ifdef __APPLE__
if (!stat("/Users", &stat_info) || !stat("/System", &stat_info))+#else
if (!stat("/home", &stat_info) || !stat("/usr", &stat_info))+#endif
{boot_info.BootIdentifier.Data1 = gethostid() & 0xFFFFFFFF;
That's some complicated stuff.
No comment on whether it's worth it. I'll leave that question to someone else.