Wanna install cfw on my majoras mask n3ds. But don't wanna lose my progress on pokemon blue. Considered getting far enough on my red with my other 3ds and trading
Unfortunately you can't use a .3dsx save tool with the new 9.6+ games...
...If you want to risk, you could downgrade to 9.2 without formatting, but you risk booting to an error screen only and you would have to update to fix that!
If the downgrade goes alright without formatting, installing CFW will clone your SysNAND into EmuNAND, and then you'll format SysNAND, but all your contents will still be on EmuNAND.