I was thinking about it being introduced on all vehicles, to do that for just ebikes would cost so much per unit that it will kill the market overnight.A rough map is probably necessary for context, though the usual details would not be required as the speed could be calculated from distance/time. It is irrelevant if a side road is running parallel with a dual carriage way because the assisted speed would be limited to 15mph. The law ought to concentrate on dealing with those who drive/ride/cycle irresponsibly rather than try and outlaw those who don't.
Cost aside I'd just wrap the reciever in foil and disable it.