As much as I'd love to use the stock SMS Messaging app, this bug is a deal breaker. I'm in multiple group chats that are active enough to where I really don't want my phone to vibrate per each message sent. Even when I disable the 'Notifications' slider for the conversation, I will still get them anyway. Issue still persists after updating and rebooting. I'm using a separate user profile from Owner in case that's relevant.