In short: Unless you are certain that you are using manual voltage mode (VRM controller, from the bios) do not use the application ("worktool").
It is a CPU killer if the VRM controller is running in offset-mode.
I tried it with the voltage mode set to offset (or "Auto") and setting 4200MHz for CCX0/1 and 4050MHz for CCX2/3 resulted in 1.405V actual Vout during Cinebench R20.
The voltages during the default OC-Mode remain sane, regardless of the VRM controller operating mode.
This hack however causes the voltage governor to go insane.
I have no idea why someone thought it would be a good idea to release this to the public...