The original fan spacer works great. I wanted some light down by the print nozzle, so I could watch the print without using a flashlight. I modified the spacer to add an area for LEDs. I stuck a small strip of LEDs on and wired them into the extruder fan power.
I'm quite happy with the result. Soldering into the existing fan wiring (while it was still on the printer) was a bit of a PITA. I didn't want to completely undo the loom and remove the fan from the printer, so that's how it had to be. Still, well worth it.
I printed at 100% infill. Once you print the walls, there's not much left on the inside I figured why not. Print with supports and a brim. Print in the orientation shown on the model here. Its minimal support and it comes off very easily.
I bought a meter long strip of 12v LEDs for about $1. I cut off a 45mm section and attached it to the bottom of this part. I soldered on servo wire, and then soldered those wires to the power leads going to the extruder fan. For extra security, I put some Kapton tape around the LED strip as well (also to cover up the exposed solder points).