FunKiiU was pretty well known for patching the dlc and demo tickets properly. It does, in fact, require some 'magic' to be written to the ticket. It's in Python but I'm sure you will understand whats happening. Check out the source here, look at make_ticket() and patch_ticket_dlc()I guess DLC needs some extra ticket magic. If anyone knows more about this please tell me so I can fix this.
https://github.com/llakssz/FunKiiU/blob/master/FunKiiU.py#L198