In the notifications scheme, how about an option to wait 2 or 3 minutes before sending out a notification, in case there are any updates to follow?
Almost all of our bugs involve someone creating the issue, and then attaching a screenshot, and often updating part of the bug they missed (like component or assignee), resulting in 2-3 emails per issue.
Optionally, the problem could be alleviated by making "screenshot added" a distinct event from issue updated. Or making a "quiet save" option and leave the control in the users hands.
Email overload is my biggest complaint of jira right now.