I use the speed signs that show constantly on my car’s satnav more so since the introduction of in town 20 MPH limits because you never know what speed your actually supposed to be doing these days.
There are places on main roads here in Bristol that are 20 MPH then change to 30 MPH for a couple of hundred yards then change back to 20 MPH, I kid you not but having that speed sign is heaven sent when I’m in less well known area’s of town and the bears with cameras are about.
That said 20% of the time the speed limit is incorrect so they need to fix how often these systems get updated before they even think about automated road signs.