This small platform will allow you to mount BTT USB-C input shapers to a 40mm fan while leaving enough clearance for airflow.
It shouldn't have any issues printing flat-side down without supports. I printed in PETG with 20% Gyroid Infill.
The input shaper mounts to the platform with M3 screws and some nuts on the back-side. The platform mounting holes are slightly larger to match most fans, I just used #6 self-tapping screws into my Satsana duct.
The author marked this model as their own original creation.