currently you will not be able to use the save and it will start fresh.Animal Crossing is a special game whose cartridge type is Card2.
Card2 games' save is stored inside the ROM itself.
You should dump the ROM and rename it into .3DZ in order to use it in GW mode.
currently you will not be able to use the save and it will start fresh.
Is that really true? At the very least, OP can use savedatafiler on the .3DZ to extract the save, and then import that to a .cia version of the game. I know the cartridge version had some dependencies to the SD card, which is why this would not work as you say. But since a .cia version of the game would use the SD card by itself anyway, this would probably work given SaveDataFiler can read the save directly from the .3DZ file (since AC:NL is a CARD2-type game). I can't back this up by saying "I tried it and it works," but I don't see why it wouldn't.
Since the .CIA version of the game ignores encryption variations could you then do the reverse and take the injected save and put it back on the retail cartridge whilst in 4x sysnand to make it compatible with classic mode?
To be clear, it doesn't ignore encryption, but rather it uses encryption from version 4.5. However, in order to get that save to a retail cart, you would need "CFW" running from the SD card of your 3DS. This is currently the only way to run savedatafiler while also being able to access retail carts, and you absolutely need access both in order to put your save back. Installing CFW is a very glitchy and time-consuming task (it literally took me 4+ hours to get it working), so if you're out to to that, well... good luck.
So retail games cannot be used/seen by Gateway's EmuNAND which unless you're running CFW is the only place one can also install savedatafiler?
Animal Crossing is a fw 4.5 game. It doesn't use any 6.x save encryption. You should be able to just dump it and use the 3DZ rom fine.
The save data is stored inside the rom file. Try playing your dumped game.no luck dumping the save file, but if its 4.5 game, maybe i can still downgrade and just play in 4.5 sysnand with the retail cart.