Yes, you can populate them via automation tasks (queries and sub-actions).
Unfortunately this is not true. These filed cannot be populated from ePO, they can only be read from ePO. These are registry filed on client machine which can be written during installation of MA (KB67385) or after by editing registry on client machine.
It is true I just did a test via automation tasks using Server Task Builder with Actions Run Query and the below Sub-Actions
Set System Description— Allows adding a description and four custom fields.
However looks like this sets the database but not the computers registry
I wrote a custom script that can be deployed either through third party or through EPO by using the feature in the agent that lets you run a exe after a dat file update occurs. This script will populate the custom props field with the make, model number ,serial, and the casetype. You can use this or follow the concept to put your own data in it. The script is posted here in the Mcafee forums https://community.mcafee.com/thread/27434?start=30&tstart=0