I have Ultra Plus microSDXC UHS-1 card (with adapter) SanDisk, Class 10, 64 GB SD card with running up to 80 MB/s. You could have included in Step 6-7, stating that if there’s no 2 long random name (numbers/letters) in the same file, just skip Step 6-7 altogether.

No, I simply needed to upgrade from 4 GB SD card to 64 GB SDXC card and I use 3DS XL.