Basic Raspberry Pi 3 sleeve case with an additional slot for a POE splitter(https://smile.amazon.com/gp/product/B07CNKX14C/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1).
This design came from before the POE hat for the pi, but I still prefer this solution as no fan is required.
It's a tight fit, but with some work the pi will snap into place. Very difficult to get out, which was the intention. The SD card can be inserted into the case after the pi is installed but it is difficult to remove without needle nose pliers or tweezers.
FWIW I use 70mm/s print speed and the platform is at 60C with the extruder at 205C.