I haven't.

It's part of discussions around hypothetical futures where everything is self-driving and the vehicles communicate with each other to form dense convoys on places like freeways where there aren't pedestrians.

I certainly haven't heard any mainstream suggestions that self-driving taxis ought to drive faster than humans in spaces they share with human drivers and human pedestrians.

> I've seen plenty of robotaxi huckers advocate for speed limits 'appropriate for robot response times'

Where?

I think maybe robotaxis should have speed limits appropriate for driving into trees and fire trucks.