@Gerry
Yes, it would be similar to the way that we currently e-mail from within the ticket, but instead of e-mail, it would be a Teams chat instead, with somehow being able to add this to the timeline, so should someone else pick up the ticket through a hierarchical escalation, they are able to see what has already been communicated/discussed/attempted with the user.
Thinking of it again now, if it can be from a 'central' user (might be something we would need to configure on our side, thinking out loud) that would prevent individuals from being 'targeted' outside of Hornbill for future support would be beneficial, like we have the Hornbill mailbox that sends out the notifs regarding the ticket status etc.
I've not looked further into what @samwoo or @Berto2002 have mentioned yet, or if I have, it was a while ago now, so will need to revisit that suggestion too.