Regular presentation are only controlled by the author. I made a special case for the demo. Yes, there should be a unique-sync code for each visitor to the demo. I though the universal sync would be collaborative. Might have been my mistake.

I wouldn't change it. When it is going crazy it only reinforces the power of the Sync tech you are doing.

Good advice. The happy medium is a unique code for each person who click the demo link. Firebase would make this easy. Thoughts?