Try this to see if it helps you -
If you only have a small nmber of users, have them choose different media types in thier document - pick ones listed in the driver that are of similar density as labels - heavy weight, card or another type.
These types, when sent to the driver, set speed and temperature settings at the printer to allow fusing to occur properly for different media.
One user can send thier jobs - Tray 1 Load Label
Another could arrive - Tray 1 Load Card2 etc.
Give it a try, that way each person can have a unique media type for thier labels and other users could then know which person sent it.
Update the firmware to the latest and install HP software - there are also places to add custom documents.
I dont know if this device has it but you could use Job Storage. The dirver can send the job to the printer and wont print till its activated at the printer picking it out from the Job Storage menu.
