So I came to an idea. What if you have a friend with one of the 4 DSiWare games? Would it be possible to backup the SD Cards and format the system so the NNIDs are unlinked? Then you could link the NNID on the target 3DS and redownload the DSiWare game? Don't ask why I don't borrow his 3DS for system transferring. He lives about 100 - 200 km away from me.