It just unlocks the shaders it doesn't OC or mess with voltages or VRAM or anything?
Where can you download RBE v1.28?
Сorrect, just the shaders, no overclock or voltage changes. There's a new check box under additional features. Just check unlock 6970 shaders. Save bios and you're ready to flash. You can still overclock after unlocking the shaders.
https://bittention.com/software/radeon-bios-editor-rbe-v1-28-download/