Hey @jamie k! Daniel from Customer Support Engineering here 🔧
At the moment, it isn't possible to open the Messenger on the most recent conversation of a user. Opening the Messenger on the conversation list with Intercom('show') is the closest functionality we have like this 👍
If this is something that you'd like to see implemented in the future, make sure to drop it in our Product Wishlist Group 😊 And remember to keep your eyes on our Built For You page to stay up to date with all of our latest product announcements and updates 👀
Thanks! We found a work-around by opening the Messenger into a new conversation and setting up a bot to reply to new conversations.