> spoofed locations that are physically impossible to receive by said receiver?

Wait until you hear about Sporadic-E or Aurora. RF is a weird place full of natural phenomena making the impossible very possible.

But even if that was the case, is there any value for a receiver to be receiving those? Surely those messages would be picked up by a receiver closer to the transmitter anyway. I think the value in spoofing rejection is greater than the probability of a transmission reflecting from beyond the horizon and not being already being picked up by a local receiver.