This is really cool, glad to see someone making a real product out of this - have seen demos in the past.
One thing I've always wondered is if this could be made to work for group video chats - depending on the tile you are looking at, that person would know, so you could tell who is paying attention to you, or even exchange a furtive glance with a colleague in reaction to someone else said like IRL. Even harder, but also cool would be updating the gaze dynamically so you could tell what they were looking at in your scene - say you have a whiteboard behind you and you can tell when the person is making eye contact with you vs looking at something you drew on the board.
Original dev make it so! :)