The device is reminiscent of a camcorder, with a lot of optics and electronics compressed into a small volume and not a lot of consideration to repairability. There’s a lot more engineering here than a VR headset and I’m impressed how far Magic Leap has iterated the design for a developer release. That said, having a non-replaceable battery would be a disaster for a consumer release IMHO. Great teardown!
The “tl;dr diagram” has the positions of the LED light source and LCOS grid swapped: Light from the LCOS will not be reflected into the waveguide. The figure from the Magic Leap patent is correct.