ROM Hack Question Transferring saves from EmuNAND to SysNAND

[SamusAranX]

This used to be so easy on the 3DS. sigh

I'm thinking about putting CFW on my Switch to be able to extract, edit, and re-inject save files, specifically for New Horizons.
I found this thread: https://gbatemp.net/threads/tutorial-how-to-move-saves-from-emunand-to-sysnand.552858/ but it's not giving me the answer I need.
I'm not interested in piracy, cheating in-game, or modding games. Literally the one thing I want to do is copy my ACNH save to my computer, edit it there, then put it back on the Switch.
Preferably on SysNAND because I want to go online with ACNH every now and then.
Is what I want possible? I know that "can I get banned for this?" is not a question that can be answered with 100% certainty, but I'd prefer not losing this Switch to a ban.

Edit: The title is somewhat misleading, sorry. I wanted to change it to something else but forgot, and it seems it's not possible to change the title after posting. welp

 

[supaastahhmarioo]

‘I'm not interested in piracy, cheating in-game, or modding games.’

‘Preferably on SysNAND because I want to go online with ACNH every now and then.’

sounds a lot like cheating lol

 

[SamusAranX]

Literally the one thing I want to do is copy my ACNH save to my computer, edit it there, then put it back on the Switch.

This is literally the sentence after the one you quoted. If you have nothing to contribute, don't.

 

[supaastahhmarioo]

This is literally the sentence after the one you quoted. If you have nothing to contribute, don't.

wonder why no one else has commented ? Ok then

 

[The Real Jdbye]

This is literally the sentence after the one you quoted. If you have nothing to contribute, don't.

Still sounds like cheating. If you mess with save data, especially in an online game, you risk getting banned.

It's not that it's harder to do on Switch. Checkpoint exists for both 3DS and Switch. It's just that Nintendo actually give a shit on the Switch and they have a history of banning people who cheat or use hacked saves online even on the 3DS, but there it was just in Pokemon AFAIK, and that was just a game-specific ban.

 

[Goku1992A]

To answer your question it cant be done. They will ban you.... you would need 2 switches to do what you are trying to do

 

[Eclectic Pseudonym]

There's a tutorial on a more complicated and ostensibly-safer method of transfering/modifying Pokemon/ACNH saves without ever booting into CFW sysNAND (can't post links whoops but search the forums for "Edit OFW clean Switch save data from NAND backup/restoring via Fusee Gelee payloads"), but realistically all this boils down to a good news/bad news thing:

The Bad News:
The upshot is there's 2 different things to (potentially) worry about here, with the checks in two places:
1. Nintendo detecting that you've CFW'd your Switch, when the Switch connects to the internet at all
2. Nintendo detecting that you've modified your ACNH save game/game code, when the Switch connects to the internet while actually playing/interacting with ACNH

The link I posted (ostensibly) evades the 1st check by dumping/editing/reuploading the entire sysNAND, which means you're never actually launching into a CFW-modified sysNAND in the first place. However, that doesn't change the fact that if there's a check on the Animal Crossing servers themselves that detect modified save games or game states, check 2 will always be a potential concern when you're editing a save file. The only truly safe way to bring in modified/duplicated items would be to use a hacked Switch to local-multiplayer trade items to a clean Switch, and I only say that's "truly safe" because if Nintendo started banning clean Switches for even trading with hacked Switches, Nookazon and the entirety of the online ACNH community would collapse overnight because nobody would be able to trust that the person they're playing with is "clean". If you don't have a second Switch but can borrow one, you could also edit your save file, launch it in emuNAND, trade items, relaunch your non-modified sysNAND, and trade back.

The Good News:
Based on the "Animal Crossing: New Horizons -- Ban Discussion Thread", nobody's been banned for merely save editing yet. Plenty of people have simply booted CFW sysNAND in airplane mode, JKSV'd their save file, edited it, and reinserted it into sysNAND without being banned yet. The only bans that have come down in ACNH so far appear to be "If you launch the game, while online, running CFW, and use tools like EdiZon that modify the memory in real time", although where the flagging occurs during that process is an open question. There is no guarantee that that will continue to be the case, but the lack of competitive multiplayer or in-game monetization does mean that the odds of them spontaneously deciding to crack down on things in the future isn't spectacularly high in my opinion. For what it's worth, I've so far not run into any issues with the riskier sysnand-cfw-jksv method, but I'm also spending the shortest amount of time possible in sysnand-cfw, triple checking it's in full airplane mode beforehand, and willing to risk the price of a replacment unit on it in the event things go sideways.

The tl;dr:
In order from most safe to least safe (from a potential ban perspective), getting items from an edited save game in order from most to least safe are going to be:
1. Don't do it
2. Trade from a hacked Switch to a clean Switch via local wireless
3. Dump, edit, and reinject your sysNAND
4. Boot into CFW sysNAND in airplane mode to dump/reinject the save via JKSV.

 

[Th3Alic3]

You can do this with SysNAND (CFW) and SysNAND (OFW). I do not recommend this because you need to remember to have safe DNS servers manually turned on every time you jump to your SysNAND (CFW) side to use Checkpoint. It's really easy to forget to do this (ie. I got a ban this week as after the OFW update I forgot to re-enable the misdirected DNS while in CFW. I also recommend you preform your full back-up from Hetake. It's the only way to undo that eff up.)

Also, it should go without saying that the ONLY way to pull this off is to not have any illegal backups on your system.

But, yes, if you don't slip up after a year like I did... it works and you will never be banned. I was doing this to send my saves onto my non-CFW Switch after making a back-up in Checkpoint for close to a year.

 

[BoNyKiD07]

I have a similar question - I want to do something similar but literally just do something like restore and backup my saves to duplicate items. E.g., I have a friend visit my island, take and item, and then restore my island to get it back. Is using JKSV the best option for that? Or easiest option to do it quickly? Is there a tutorial on it including how to do the safe DNS servers thing?

Edit: The link says specifically not to do it for animal crossing - if I'm not hacking or modifying anything but just getting an item and backing up and restoring, is that method better than JKSV? I haven't modded my switch yet so I'm still deciding if I should go with stock or CFW sysnand - it seems like JKSV only works with CFW sysnand but that's frowned upon right?