Read receipts are currently unavailable (on the agent side) on the very last client message in HS conversations. So if during the conversation an agent had to spend some time finding an answer, and then responds to the client, there is no way to see if the client received our update (screenshot). Therefore, since we don't see whether our last response was read, we don't know if we need to follow up with the client via another communication channel.
I discussed this with HS support in this ticket.
