Hearing Crickets I thought I'd share settings that, so far, seem to be quite an improvement over where I started. Starting with the Prusa settings at 0.15mm layer height, generic PLA, and the MK3 .4 nozzle profile, these are the changes:
First Layer Speed: 10mm/sec
First Layer: 220/65
Other Layers: 215/65
The higher retraction is a tad worrisome since, while E3D says you can go up to 2, they said no more than .8mm for PLA should be required. Going to 1.2mm is passable for some models but stringy for others and .8mm tends to be a mess. If I lower the other layer temps much below 215, I get layer adhesion issues.