Anyone have any recommendations to remedy this surface scarring? Long extrusion lines running parallel to the exterior perimeters seem to give the worst results. Turning the top surface extrusion lines 45° to the exterior perimeters is an improvement. I do also see this now and then on surfaces the quickly transition from a long extrusion stroke to a short curved portion of a print. See example photos. Could this be a case of too much nozzle pressure towards the end of the extrusion? Bed is flat, filament is calibrated, and fresh printer calibration.
Have you tried calibrating the filament for pressure advance?
Welcome to the forum.
From the pictures you provided it looks like your models are warping up on those section and this is what is causing the poor surface finish. As the model warps up it puts pressure on the nozzle and the extruded plastic has nowhere to go but out the sides.