You can only have one SpeakerTrack 60 per endpoint, it's not possible to use more than one, as it and the endpoint aren't designed that way. I doubt something like this would be implemented, the SpeakerTrack system is meant for a certain room size, and isn't meant for larger rooms where the required FOV is wider than what the cameras can detect. You'll have to reach out to your Account Manager to see what might be on the roadmap as far as features etc.