I still fail to see what Agents of any type has to do with any of this. This cost for light agents is something I have not seen but it isn't an isssue for us.

Light Agents can only work on tickets using internal comments. Light agents can ALREADY be added to tickets via triggers.

This request was to add a CC (a standard user) to a ticket via a trigger as you can't do this currently. That being a standard user account so that they were automatically included in on a ticket where required.

The only reason you have agent level accounts is to control a ticket and to make internal comments that the end user does not see.

It is issues like this that sees Zendesk lose customers like us as they do not listen.