Slight clarification; You would do this by either
A. Making a fresh save, make a backup with something like JKSV, modify that save with a single Powersaves code, make a JKSV of the modified save, then find all the differences in a hex editor (Cart only)
B. Make a backup of a game save, modify a value (modifying others minimally as possible), saving, making another backup, and rinse repeat like 8 times and find the value that consistently follows your changes (don't modify said value in the exact same way every time tho, or you'll end up with multiple consistencies)
If your Powersaves works, then you could make a backup with JKSV of one of your games, apply a single cheat, make a new JKSV backup, and note the difference
This is all that's stopping me with making the Sm4sh one... Namely with the unlock all characters code (but some other ones as well) there's a TON of value changes... and It isn't very fun tapping A ~52 times XD
So new release hype