So this is interesting. I imported my saves successfully, but instead of them appearing in the game, there was none. Here's what I've noticed, though, and this might be relevant to further improve the application;
1. Stella Glow has three save files, even though it has two save slots; SaveData0.sav for the first save file, SaveData01.sav for the second, and SaveData02.sav for the suspend save (which you can do at any point in battle).
2. Upon importing all three save files, SaveData02.sav is the only one that was on the game I was importing to at the time, since I didn't have any other save files.
3. The suspend save is the only one that appears to have successfully imported; the first two saves don't appear in their respective slots, but the suspend save works fine.
As a result, it seems that, if this isn't the fault of the game itself, the application only overwrites the save data if the file already exists, and it doesn't add it in the situation that it doesn't exist. I'm not sure if svdt behaves the same way, but I intend to check. Regardless, this is a minor issue, but an annoyance nonetheless.