Disable typing indicator for messenger

We use messenger as a support channel, but we don’t treat it as real-time live chat. It would be helpful for us to be able to turn off the typing indicator bubble for our messenger, since we don’t want to set unrealistic expectations for our customers that, if our agent is typing, the customer will get an immediate response. Sometimes agents start and stop typing several times over the course of 15-20 minutes while gathering details before they actually respond to the customer.