Wouldn't the CFW on this thread allow you to do that? I recall someone saying this CFW can be used with 6.0+ save management, so correct me if I'm wrong, as I'm not familiar with Sky3DS. Are Sky3DS saves incompatible with even cartridge-mode Gateway games? I would have thought the .sav format would be the same. eShop-mode saves are certainly different, but that's why this CFW is so great. We could take a Pokemon Alpha Sapphire save, for example, from a retail or Sky3DS card, and convert the save to the eShop equivalent, which was previously impossible without a Powersaves device.
So back to what I was saying/asking: cartridge (non-eShop) games don't work with Sky3DS saves (which are also cartridge based)? Not even unencrypted/<6.X games? Because if encryption was the issue, this CFW would handle that, I would think.
The .sav format between SKy3DS and Gateway are definitely not the same. AFAIK there is in fact a tool named 3DSsavTool which claims to be able to convert between the two, but it is obviously only a beta and there are still many problems. Unless there is a real tool which can easily convert between the two, I am reluctant to buy another flashcard.













