Decided to forgo the entire USB-C nonsense and just stick with the built in micro-USB on the Pico. Printed a new housing top to accommodate the different connector location, but I should still update the PCB design in KiCAD to remove the USB-C and fix a few other issues like the trace gap width and the pad extensions for the castellated contacts on the Pico. Installed the entire system and attached 2 fans to my roof ducts. One fan attachment used some 3D-printed screw adapters, and the other just used magnets. I used wood-glue coated cardboard as a low-cost water-resistant barrier on the ducts, which worked pretty well. The overall system worked pretty well. It dropped my attic temperature from around 90F to around 83F in 2.5 hours.