Thank you for your detailed how-to using REW and SigmaStudio's AutoEq block.
Is it possible to add weighting to the REW output file in SigmaStudio e.g. B&K or Harman "House" Curve?
I put a two channel parametric EQ before the Auto EQ block. That way it's easy to dial in a house curve of choice (or none at all) without having to re-do the Auto-EQ calculations.