Tickets and signatures are already using the same tinymceTicket
custom configuration:
Tickets:
<textarea class="form-control tinymceTicket" name="ticket_reply" placeholder="Type a response">
</textarea>
Signature:
<textarea class="form-control tinymceTicket" name="signature" rows="4" placeholder="Create a signature automatically appended to tickets, emails etc">
[...]
</textarea>
tinymceTicket is defined in app.js