We also know that the Acer mixed reality HMD has an accelerometer, gyroscope, magnetometer, and proximity sensor.
The first three are the standard ingredients of an IMU. The last is probably to warn you before bumping your head into something, I'd guess.
In a demo, we saw that at the very least the Acer mixed reality HMD has no passthrough capabilities, and it’s a fully occluded headset, so you can’t see through the lenses, either. It also doesn’t do any sort of “merged reality” like Intel’s Project Alloy does
Maybe it was originally intended to support passthrough, but the quality just wasn't there. This might not have been a very painful feature to cut, since I think the use cases for tethered AR are probably rather few.
Anyway, did you try it? Reactions?