Most highend Z790 mobo have overkill VRMs, so it might not be an issue.
I would suggest the Asrock Taichi for the sane pricing and the feature set compared to the Asus Strix, Gigabyte Aorus master or MSI Ace boards...
But although, did you read the reviews about 7800X3D? its the current gaming king cpu with less power draw and thermals and doesnt need a top of the line mobo...