When smb submit a ticket i usuallly leave a reply and set status to Under review. But i don't like that this trigger two separate emails sent to a user.
I also do not like posting reply to the form that chages the status because it does not allow to have a consistent thread of comments ("status rely" is replaced and it s not clear at which moment in conversation it happpened).
Why don't you just add possibility to change status with commment OR let admin choose whether to send email or not? Possible there is some other smart solution of course.