Maybe I’m drawing conclusions about what these beacons would do, but if any of the things you mentioned stop working, I can still drive and won’t go full speed into a wall. I don’t have the same confidence in these beacons.

Why would a car that is having trouble orienting itself go full speed?

Software bug? I think you’re dodging the point a bit - going into a wall at any speed is bad.

Alternatively, say it has trouble orienting itself and slows down. That can be just as dangerous if cars behind you are going fast (e.g. a highway).