We will consider adding a new permission to allow customizing the ability to delete tickets.

Hello,
 
We met yesterday to discuss the requested features list for future versions of SmarterTrack, and I'm sorry to report that this change is not on the roadmap at this time. Please note, however, that the ability to delete ticket comments is limited to agents with the Manager role or the agent who created the comment. 
 
We'd like to thank you for your feedback and apologize for any inconvenience this causes. If plans for the future change, we will be sure to post an update here.