So I got OoT3D recently to install homebrew on my New 3DS XL, running on the latest firmware. After some tinkering around, getting the save injected and all, I finally got homebrew working. Yay!
I've tried four times already to downgrade. It does it successfully with no errors when downgrading. First time with the sysUpdater update for N3DS and the next three were with safeSysUpdater. However, each time I did it, I had a soft brick upon boot, where I had to boot into safe mode and update to fix my system.
I ran the downgrade files through SafeSysUpdater, and they're all okay. I posted about this on Reddit, and it seems like the solution is to format my system in order to downgrade. Is this the only way to do it? I have Pokemon Yellow and Tomodachi Life, which can't have their save data backed up...
I think you can back up Tomodachi Life save using svdt. I used svdt to move a save from a hacked o3DS cia to a non hacked N3DS with a Sky3DS sav file. Worked like a charm.