Is there a way to create new placeholders for internal and public notes?

I am looking to add the functionality of inserting time in a ticket comment using the placeholders. The information regarding the time zone of the assignee/requester/current user is in the profile, so I was wondering if the following placeholders could be added to provide this functionality for Macros: {{ticket.requester.current_time}}, {{ticket.assignee.current_time}}, {{current_user.current_time}} etc. 

Case Use: Insert macro for an internal note that logs the exact time of the macro being used for easy copy/paste externally (Side conversations/slack/etc.) rather than looking through the history to see the time stamp. -- Timestamp shows when the note was saved/submitted, rather than when it was initiated with the macro --