The JP release is 3.65 (including the 1.02 update). You can modify the save file to switch into other languages as well. Using that method you can use nonpdrm and not need maidump, at least on 3.65.
3.60 would still need maidump though :)
There is a few tutorials on how to do this
Take a look at these:
https://gbatemp.net/threads/tutorial-how-to-inject-loadiine-saves-to-system-usb-video.445689/
https://gbatemp.net/threads/how-to-use-your-loadiine-saves-with-usb-nand-installed-games.445586/
The installer looks to the /Install folder on the SD Card so you can only install a single game at a time. Once installed, copy the files for the next game to the /Install folder and install... what he's saying is you can't copy multiple games to be installed to the sdcard at the same time.
I was playing around w/ that myself and ran into the same issue. I'm guessing the rednand support isn't quite there yet.
Try deleting your prepatched firmware and see if it works then.
If not, I put in a pull request to update the RedNAND detection
There is a branch of rxTools for A9LH but it's not very mature yet, if not "experimental"
I have it on my O3DS and it works.
AuReiNand or Cakes currently have spent more time in solidifying A9LH
Just going through the process on my n3ds and with .63 I'm getting the "CTRNAND is not slot0x5 encrypted!" error message.
This is the full error message:
Using EmuNAND @ 3B0000/000000
NAND CID: 52B3471A950030454732303000011100
CTRNAND is not slot0x5 encrypted!
Unbrick FW 2.1 EmuNAND: failed...