It's taking 900 mV using overdriveNTool, on hwInfo it's drawing 0.881V just like my previous ref vega56. (Still unsure if this is the core clock power draw or mem clock power draw) This is with registry edit so the undervolt works, compared to ref vega 56, my on the wall power draw has been reduced by about 30 Watt. I imagine the power draw should be the same as ref, the difference is likely due to me running ref vega 56 at 64 BIOS (higher mem/core clock power draw @ 1.35V).
For reference,
before: r7 1700 + rx480 8gb + ref vega56 (64 BIOS) -> ~ 400W
now : r7 1700 + rx480 8gb + strix vega56 -> ~ 370W
So it should be safe to assume that ref and aftermarket are about the same, except for the slower memory. Did you use the same registry tools (and .reg files) that you used in the ref card (I guess they're the same)?