Canned Responses for Jira support mentioning people while putting templates in comments.
Jira uses markdown to generate rich comments and we need to generate piece of markdown as well to make proper mentions. See Jira WikiRenderer documentation.
|Particular User||[~username]||username is Jira username of user you want to mention|
|User Picker (single user)|
|Field Name and 10000 are Jira custom field name and id|
You don't have to do anything. Canned Responses will generate usual Jira user mention. Email notifications will be send according to your notification scheme.