A Qube farm can contain a mix of machines that users never log into, such as machines installed in a rack in a server room (dedicated workers), and user's machines that are available when they're not in use (non-dedicated). Qube does not naturally differentiate between dedicated and non-dedicated workers, it assumes that all unlocked machines are equivalent.
If you wish to have the supervisor "prefer" to send jobs to dedicated machines, you could add an artificial host property such as "host.dedicated" to all workers via the qbwrk.conf, setting it to "1" for dedicated machines, and "0" for non-dedicated.
Via the worker's local qb.conf:
Set (or add to) the worker_properties value to make a dedicated worker:
worker_properties = "host.dedicated=1"
...or a non-dedicated worker:
worker_properties = "host.dedicated=0"
Via the central qbwrk.conf:
In the [default] section of the qbwrk.conf make all workers non-dedicated:
worker_properties = "host.dedicated=0"
...then, in whatever section of the qbwrk.conf you define the dedicated machines, (or in each dedicated machine's block in the qbwrk.conf), you would set:
worker_properties = "host.dedicated=1"
Then, all your jobs would need to have their "hostorder" value set to "host.dedicated", which will result in workers with "host.dedicated=1" receiving jobs before the non-dedicated machines.