I don't know if this is still relevant, but it was my breakthrough of the week last week so I'm pretty excited about it.
Anyhow, I found it much easier to get Save Game Manager to connect to an "Ftp Server" app (thats the name of the free App that worked best for me and it's super simple) on my Android tablet.
The best part of using android is that It can make a Portable Wi-fi Hotspot so you dont even have to have internet access or mess with router setting/compromise security. Some FTP apps wont connect to a network being broadcast by the same device though, if your interested I can post the specific publisher of the app I use.
For reference, I used a DS lite, R4igold3ds, and android 4.2.2; also, I can confirm that it will not work in any config. on a DSi.