First off, thanks for all the replies :)
I removed the following: SMCBatteryManager, SMCLightSensor, FakePCIID, FakePCIID_Intel_GbX, and the old SmallTreeIntel kext
After adding the new SmallTreeIntel kext I shut down, turned off the power supply for 10 seconds, checked that MSR 0xE2 was still...