Update:
So AMD has cancelled support of a method I used to report temperatures like HBM, Liquid, VR, VRM in the latest Crimson ReLive.
They have replaced it with a new method, but that one gives me the same value for all temperatures, even those that are certainly not present on a particular board (i.e. HBM or Liquid temperature on an RX 480).
Working with AMD to resolve this...
I cannot reproduce the VDDC problem, for me it gives correct values in idle and load too.