I'm not sure if this works, but you can lower the backlight using NTR CFW version 3.6. It gave me an extra hour longer than usual gameplay without it. If it doesn't NTR CFW is still useful to have.
I like that games can be fixed after the fact, hate that it's being abused via beta tests... And DLC... I was a 7800 owner back in the day and loved Impossible Mission, turns out I couldn't beat it because it was actually impossible lol