I wanted to improve fan cooling for my Dragon HF and I found a video testing idea with this kind of grid which helped to solve turbulence, so I tried this. It improved airflow significantly because now I am measuring speed of airflow 2.8 m/s vs 1.2-1.4 m/s before. I am using it on ZOrbiter, but it should work with original extruder as well.
The author marked this model as their own original creation.