Yes, most likely the grain direction affects tearout, as well as cutter sharpness and material, specific type, density and quality of wood, speed and depth of the cut. Lots of variables. Tried 'sneaking up' on the cut but didn't notice a whole lot of difference in this case. Haven't tried HSS bits, supposed to have a sharper edge than carbide which might make a difference. Yes, the male inlay walnut was done in one piece. For this piece I think I just need to do it about double the size, and could maybe retain all the detail then. Those failed inlays are only 1/32" (0.03) wide, so glue and time could affect results when sanding off the excess, too. Maybe I needed to be a little more patient. I used Titebond II for glue.