To add to this, I figured out why I missed that feature at first. Maybe the translation for the button could be improved on systems with the language set to 'German'.
This is the current translation:
'Zurücksetzen' means 'reset' and to me, that does not indicate that this button can be used to manually reverse the orientation.
Imho, a better translation for 'reverse' would be:
Die Tracking-Ausrichtung wird manuell umgedreht.
But to reiterate the root issue: I think the biggest problem with the removal of auto-rotation is user-friendliness. There is no indication whatsoever as to why your hands are not showing up. The device is on, device status is all green. Only if a user starts the visualizer they might see that the image is upside-down, but even then, I wouldn't necessarily expect a casual user to know, that that's not intentional. In that case the device really is not plug-and-play anymore. It even took me a while to figure out why hands were not showing up just now and I've been using LM for years.