I'd love the ability to submit a public and internal note at the same time.
When we escalate an issue to our engineering team, we like to give the customer an update to let them know that it may take a little longer than normal to find a resolution. At the same time, we need to assign the ticket to our 2nd level support group and leave an internal note with the details of what's going on.
Currently all we can really do is submit a public reply and change the ticket's status to Open so that we can find the ticket easily, assign it, and leave an internal note. If we could do all of that at the same time, it would be life-changing! Or it will at least save some time. :)