Try this:
Code:
$ settings put global key_custom_side_key_short_press_enable 1
And if you don't like it, put it back to zero.
I believe it will make the buttons scroll, but possibly in a screwy manner and not working like normal PgUp/PgDn.
Edit: And if you're still not happy, give me a copy of your boot.img so I can check the dtb.