It originally was using a DSi to transfer Sudoku that you could get from the easy Sudoku installer, and I realized that did not work. I then realized I downloaded Four Swords when it came out and I wondered if that would work. I backed up DSi's NAND, transferred Four Swords to my 3DS, and realized, it deletes the save. The only way to do this is if you bought the game or downloaded Four Swords when it was on the DSi shop. After that, you would have to get s save writer (might exist, if it does this might be possible) and you could run the DSiwarehax and get B9S that way.
As you found out, it doesn't transfer the save, so it won't get you there on its own. It would allow you to get B9S with just an ARM11 entrypoint + and ARM11 kernel exploit (usually you'd also need an ARM9 exploit as well), however, the last public ARM11 kernel exploit was patched on 11.3 (as well as the last public ARM9 exploit).
Can't directly reply... new member form rules...
Anyway if there was an ARM11 kernel exploit, this would be practically useless because someone could downgrade or install a legit CIA of the exploitable DSiWare.
Still, would be nice if DSi Transfer doesn't delete the saves, which would make everything way easier.