yes you can use decrypt9 but, because your secure info a file is not signed, you edited it and broke the signature, you need a different way to load cfw, your edited secure info will break the system.No, I don't have A9LH.
I just use O3DS, the sysNAND is 4.4. I use mset to boot to EMUNAND.
On youtube, there is a teaching course to change the region of secureinfo_A
I extract my O3DS's secureinfo_A and successfully modify it to JPN version secureinfo_A, and then I successfully made the JPN EMUNAND with my modified secureinfo_A.
Because I heard someone has already tried to use hardware flash emunand to sysnand and he has already successed.
But now, we have software (decrypt9) to flash NAND.
So, I think it may success.
i recommend to get a9lh, you can fix this.
or, find a real dumped, not edited japanese secure info a file