Any way to play a fake-signed save on retail disc?

Here's the story: I was really spoiled with Nintendo CFW, and I'm not really enjoying the long list of cons of staying on a lower firmware. While I'm probably not going to update, I would like the option to. I've been playing Final Fantasy XV on a fake-signed game for 20 hours or so and I'm really loving it. If I decide to update my console, I want to buy the retail version and transfer my save file over before updating. Now, again, spoiled with Nintendo CFW, so I assumed you could do this....

Any way to play a fake-signed save on retail disc?