Not sure if this will help or not but have done a bit of testing today and have taken the following images for you:
All I have done is change the CPU Multiplier to X20
and disabled all of the Turbo Core features. Everything else I have left at AUTO.
I then altered the CPU Voltage control to 1.4750V
I did encounter a problem here. When I saved the settings to BIOS and rebooted, the system crashed whilst trying to load Windows. When I went back into BIOS and checked the voltage had defaulted to 1.3000V. I had to reset the voltage from this figure (+0.175V) and save to BIOS again before it was accepted.
Checking under PC Health it showed the voltage as 1.504V
Once into Windows EasyTune6 showed the CPU Voltage as 1.480V on the main page:
but as 1.500V on the HW Monitoring page:
Running HeavyLoad, to stress the CPU the voltage dropped to 1.440V when the CPU was under maximum load.
The voltage fluctuated slightly as I ran the test between 1.440V and 1.420V
The CPU Temp has varied between 40 - 44C
But, I am running a Noctua NH-D14 cooler and the ambient temperature is only about 20C.
I haven't had a chance to fully stress the system but, from the testing I have been able to do, it seems solid and I have not encountered any issues with any of the tasks I have run.
Hope this helps.