I wanted to have a discussion about linear advance and how much improvement I noticed on my Ender 3. Before I upgraded to direct drive I think linear advance was the one single upgrade that really made a difference in my print quality. I noticed immediately that my stringing was non-existent after properly tuning my Linear Advance settings, as long as I kept the retraction settings around 4-5mm @ 35mm/s.

Now, many people are intimidated by the Linear Advance option. It's really not that hard if you use the proper calibration tool and enable it in your firmware (I recommend Junction Deviation at the same time). The calibration tool at the Marlin website is the only thing I have ever needed outside of the firmware changes.

https://marlinfw.org/tools/lin_advance/k-factor.html

Now that I have went direct drive; I had to re-calibrate the K factor. It was much lower than when I still ran the bowden setup, but still just as effective. My retractions are still great, along with the corners on my models that are 90 degrees. I would absolutely recommend this to anyone trying to improve the quality and specs on their prints!