if you can’t wait to get a fan-addon for the Beaglebone AI : here is the link to order the pcb right away: https://aisler.net/p/SWHBYGQV

it takes the recommended Fan and allows to control it with pwm from a Pin on the Beaglebone (compatible with Beaglebone AI &Black).
It also provides an easier to reach debug header(has to be soldered the other way round as in the picture(don’t know how to flip it in Kicad3Dviewer) and a debug cutout for the BBAI.

Find the BOM and all Details here.