Here is a dropbox link to my .mem fileIf you can dump your 3ds's fcram immediately following a hard reset, you can run my script to extract the game's dsiram and possibly find your save.
Instructions: Boot your DS game, load your save, press home, select return to home menu, immediately hold start, this should allow you to chainload godmode9 given it exists in luma/payloads.
When in godmode9, go to MEMORY VIRTUAL, select fcram.bin and dump it to gm9/out.
Then put the 3ds sd card in your PC and run my attached python script. You may have to change the drive letter in the script, I have it preset to F. It should then create dsiram.bin, and you can search that for your save.
Note that I had to rename the file + .txt so it would upload, so take off that .txt extension.
https://www.dropbox.com/s/532xfo36s1n1rpx/fcram.mem?dl=0