TAZ Workhorse, Layer Lines When Printing Adjacent Feature

[zifnab]

I am at my wits end trying to figure this out. I'm trying to print some generally columnar parts with inset lettering in PLA, but am seeing layer lines throughout the part that corresponds with the layers at which the lettering begins. I've tried researching this, but haven't been able to find anything that solves the issue. Mostly, the misaligned layer issues I've been reading about are a problem with the whole part, not directly related to another feature being printed. I've recalibrated my e-steps, re-tuned the heating PID parameters, played with retraction distances, slowed the print down, printed at smaller layer heights, ensured that the X and Y axes are free of play, played with Z-hop... and I still can seem to eliminate this. Has anyone else had this issue and solved it effectively? Any help would be greatly appreciated.