In my previous post (https://www.reddit.com/r/3Dprinting/s/sJv6Nw7IzT), I asked for tips on how to fix the artifacts showing in specific regions on my 3D Benchy. It turned out that there were two suspicious settings I had to tune better.
First of all, the PA value, which already looked far too high, even for a printer with a Bowden extruder.
Following another line PA test, I settled on 0.72, which improved print quality. However, some visible issues remained in the problematic area.
Second, the retraction length. Though 3.5 mm may be ok for long PTFE tubes, another retraction test showed that 2.5 mm would be more than sufficient on my system to cancel out stringing and oozing.
To compensate for the higher speed, I also increased the filament printing temperature by 5 degrees Celsius.
With all the above changes, my Benchy printed fairly acceptable!
Thanks to anyone who tried to help with suggestions to solve it!