@MaLd0n Thanks for responding! I've tried to assemble the code as an .AML file but that won't work due to errors, so I suspect I have to add it into my DSDT? I tried using it a as a patch and it set in, but gives me the following error when compiling:
Line 11961 Code 6058 Invalid Type ([Device] found, Store operator requires [integer|String|Buffer|Package|DbdHandle|Reference])
Now, when using ReHab's patch on the DSDT Laptop distro, it could compile. It has an extra line at the bottom which seems to prevent said error.
After removing a leftover AppleBacklightFixup.kext from S/L/E (oops!) I got 99% dark brightness, with very vague icons on the desktop. I fixed it by setting enabled "SetIntelBacklight" and "SetIntelMaxBacklight" in Clover, without specifying max value. Only the darkest value is now fully screen off, instead of low brightness. Not sure how to fix this, but thanks a lot for getting back to me!