Can I change the *maximum* brightness from a system file/apk?

My old Asus TF101 has a faulty backlight and cuts out if it goes above (roughly) 60%. Therefore, I am hunting for a way to change (lower) the maximum brightness that the tablet will reach - both in auto brightness and by using the brightness slider.

Following this XDA thread http://ift.tt/1DRJJBn I've discovered where to change the auto brightness (the framework-res.apk) but wondered if anyone knew where the other brightness settings were stored?

Obviously I'm rooted and fully prepared to decompile system apks!

Cheers.