This is a remix of the awesome design by emtrax and incorporates voglste's LM2596 mount as well.
This motherboard cover is compatible with both the  Ender 3 V2 and the  Ender 3 Pro.Check out my  Ender 3 V2 Silent PSU and complete the set!
My remix houses a 80mm x 10mm fan that is mounted as far away from the motherboard as possible to give you enough room to route the wires through. There's also a LM2596 mount built in.The 80x10 Fan that I'm usingThe LM2596 buck converter that I'm using
*** UPDATE: If the fan is going to be blowing air in, you will need to cut out the grill because the fan will lift during rotation and scrape against the grill. If you're positioning the fan as an exhaust fan (not the factory configuration!) then you can leave the grill in place. There's just not enough clearance for me to move the grill further out, sorry!

This is a remix of 'Ender 3 V2 & Pro Silent Motherboard' by TerraVestra
Designed to fit  Ender 3 V2, but will fit  Ender 3 Pro also.
This cover houses 80x25mm fan. An lm2596 mount with screw added, please make sure your lm2596 fits in this cover because I found some lm2596 has slightly different dimension.
This cover adds 25mm, so you'll need to raise the printer at least 30mm for better clearance.
The improvements are:
Flat bottom, no need to use support (and save your filament)
with flat bottom, you're be able to use infill pattern as mesh for better airflow.
Cutout for cable route.
See screenshot for my settings in Cura. Grid, Triangles, or Tri-hexagon infill will work.
.step and .f3d files added for easy tweak.