If mentioning a user within a comment by @ it only will show the first 5 found users. Not all available users with entered name are shown.
How this number can be increased?
Or even better, how the same functionality from choosing a user as assignee can be used for mentioning a user?
For the assignee all users will be shown supported by a drop-down-box (scroll functionality) if too many users found than can be displayed at once.