What is the current best practice to deal with having more than one Voice PE (VPE) using the same wake word. Like with the Alexa, it knows which device I am closest to.
I want to eventually bin all of my echo devices and replace with VPE devices. Does HA have this functionality? Or will I need to come up with some sort of automation on the voice pipeline side?
That's not correct, HA does have this implemented. If two satellites respond to the wake word it will pick the one that started steaming first, and you'll see the other one has the “duplicate wake word detected” in the pipeline.
In my experience it works fairly well and typically picks the correct one.
I don't know about "Echo Spatial Perception", but I remember that Rhasspy would respond to the first satellite (assuming it was the closest) if more than one heard the wakeword at almost the same time. I'm pretty sure Mike carried this forward into Voice Assist.
Of course it's a little simplistic - the closest satellite may not have the best audio quality (higher chance of mishearing the command); and it is possible (though unlikely) that two wakewords were said in different rooms at the same time.