I did the first layer test print yesterday after calibrating the probe offset. I eventually adjusted the z offset until the top surface of the first layer test was very smooth, let the print complete, and saved the adjustment to the config. Today I went to print a calibration cube, and the skirt and outer perimeters of the cube's first layer printed horribly. About halfway through the solid infill portion of the first layer it suddenly turned smooth again and the print completed properly. Attached are a photo showing the cube still on the bed, where you can see the very poor skirt, and a picture of the underside of the cube, where it goes from inconsistent to very nice.