I’m wondering what is the make/model of the fan? I have feeling the ones we have might die soon so I would like to order replacement part in advance.
In general no matter of the quality/make the small form factor fans have to have high RPM to get some airflow and combined with small ball bearing makes them fail pretty quickly. Compared to large fans where the bearing can be larger and more robust and needs only very low RPMs to get the same airflow. The lifespan of the small fan in general is much lower compared to larger fans. And have feeling this will be the same case with unleashed boards.