You thoroughly misunderstood the post you've linked.
The whole point is to inject said save into your game. (Example being you've backed up an old SD card, and you've backed up all the content, without using CFW to make a proper save backup)
But it only works if:
a) that save came from an SD card made on the same device, and
b) you're playing the digital versions of the game, and
c) you've not reformatted your device.
If you want to open saves normally, use JKSM/Checkpoint on your CFW'd device, and dump the saves normally.
00000001.sav is an encrypted save and PKHeX doesn't read that.
Using the dumping method I've mentioned above, you can get a decrypted save that PKHeX can read.