The max mem overclock I can get on 2x Vega56 is 930Mhz and 890Mhz @ 900mV.
They are giving me 1940 and 1860 H/s respectively.
Used powertables in registry and blockchain driver. Everything adjusted through OverdriveNTool without using WatMan.
Any hints on how to get more overclock?
Try flashing your card with the Vega 64 BIOS and re-applying the registry mod (use the 1100 HBM to start, to see if it's stable).
Tried flashing to Vega64 BIOS before, but the cards were drawing to much Watts from the wall

Maybe I am just unlucky in silicon lottery

V64 should not use much more power. Im using 1350Mhz and 865mV by registry mod. Taking about 170W per card from wall. Fans are between 2050-2250rpm and temps from 53-58, depending on card and how cold air comes in from window.