Thanks for the clip. Your scene really does have a ton of verticality, so first and foremost: I can see how a walkthrough mode (essentially fly mode but without up/down movement, and following stairs, like in the clip) would be useful. How does IrisVR handle floor detail, I wonder? If you had, say, a stone floor or a metal grid, wouldn't the VR user shake up/or down while gliding over the floor? I can see a bunch of this jumping on the steps of the stairs for example.
Going back to teleporting: When we talk about teleporting in busy scenes and inexperienced VR users, don't you run into the issue of them accidentally teleporting on top of objects (tables, machinery, I can even see the cursor stick to the railing at some point in your clip)? That is the main reason why we went with 100% flat floors for teleporting in the new version of KeyVR. In your scene, you would simply add cameras in KeyShot to each floor, balcony and maybe the top/bottom of your ladders or stairs. Then, in KeyVR, I would suggest using the teleport tool in one hand to explore the current area and using the camera tool in the other, to switch between your floor levels. This way your users can't accidentally teleport on top of, say, a plant in the corner of the room, or on top of the chair backrest that they wanted to stand behind etc.