I'm printing a long thin vertical piece about 2mm thick with a loop at each end. On the long thin vertical section, about five inches long it looks like the nozzle picks up plastic as it moves rapidly from end to end. The zits are tiny, like bits of swarf and annoying as much as anything as it's only a test piece, but it would be useful to know how to stop them. It's as if the nozzle picks up plastic as it zooms from end to end. Is it maybe extruding too much so it planes a little off the last layer, or maybe the cooling needs to be upped a little. I have found that 40% fan is plenty as otherwise it cools the nozzle too much and I get "Thermal Runaway" I have checked here.. https://www.simplify3d.com/support/print-quality-troubleshooting/ and I can't find an exact description of what I'm getting.