Mark a 360 VR Tour complete

So ... there does not appear to be a way to detect that a 360 interaction is "complete". I guess I mean that completing a "Guided Tour" interaction doesn't have a trigger, meaning I can't then test to see if all others are complete and mark the entire course complete. I would have to include a "Complete the course?" button on every slide, which would be stupid and confusing.

Anyone got a solution, or do I need to put text in the introduction telling the student the course just never ends? My testers are confused.

Or I could force the students to walk through the tour in a preset order, but I don't want to. Free navigation is one thing that makes it more fun.

It would be relatively simple if there was just a "viewed every Marker in the interaction" trigger that could lightbox a slide (= pop up a dialog).

I don't suppose there's a way to trap the "marker was activated" event in JavaScript?

BTW @Moderator: have you thought about having tags for things like "360 Image" and "JavaScript"?

Thanks.