In order to prevent lab downtime, I think it would be a good idea to have a pool with 1 or maybe 2 DUTs per board (depending upon availability), whose roles are to vet the next beaglebone_servo update. That way you can just upgrade that pool and check for basic servo functionality (and/or other tests) before rolling out to the rest of the lab?

An issue was encountered in  crbug.com/594163  where a lot of the servo hosts went down after upgrading the lab devices. This could have been prevented in a few ways, but could have been caught earlier had we had a staging pool like this.