Switching lessons by AR-markers, picking topics from tags was natural and easy to understand. Ideally tags could be generated by text recognition only. Markers could simply be a text-book pages, requiring no preparation on the tutor's side.
3D displays are great for visualizing scale, something that usually is left to imagination. However AR is not as useful or interesting for text-only entries.
Ability to move 3D models around, zoom in, zoom out would be helpful. Window-based interface was something that has not occurred to me during the prototyping phase. This would make the experience more hands-on, which helps with understanding and information retention.
As for the downsides, the card design I chose was not very practical. I was asked if it was possible to replace it with slides. Option to use existing materials would be very helpful with preparations.
The main issue, though, is that the technology is still not quite there yet. Cable tether was very constraining and low contrast made it hard to read longer paragraphs.
By collaborating with tutors I made sure this concept aligns with their needs and teaching methods. They noted that this UI had a potential to present complex topics in a effective way.