I've just played around with CE and had luck changing char stat values in the growth tree.
Just do a 4byte search for HP/MATK/PATK, upgrade one time, search again, you will have just one result. Change that to 99,999 (HP) / 9,999 (any other stat) and freeze it. Values will change back visually to their previous ones. But when you enter a battle, right before click on "Recommend Team", you will have ultimate powers. I did several battles now without any error messages. You can and should let the values frozen. I have to admit, that I didn't restart the game yet. You don't even need to do the HP/ATB hacks anymore, since you have over 100k HP and tons of DPS. Works for like 1 hour now.
Just do a 4byte search for HP/MATK/PATK, upgrade one time, search again, you will have just one result. Change that to 99,999 (HP) / 9,999 (any other stat) and freeze it. Values will change back visually to their previous ones. But when you enter a battle, right before click on "Recommend Team", you will have ultimate powers. I did several battles now without any error messages. You can and should let the values frozen. I have to admit, that I didn't restart the game yet. You don't even need to do the HP/ATB hacks anymore, since you have over 100k HP and tons of DPS. Works for like 1 hour now.