The reason for the skinny steering wheel is simple. As far as I know there are no heated AMG steering wheels.

The AMG system does not use cameras. In fact compared to the electronic suspension it is kind of a throwback since it just a rollbar stiffener (aka decoupler) basically the same optional system as the previous GLS550 and standard in the old 63. I hope its evolved since the old one was not very good, basically it went from jittery to floaty with nothing in between.

I'm convinced now that you're right, there are no cameras involved with the ARC, AMG Active Ride Control.
However there is little similarity to the ones you mentioned, and it has evolved. Different tech.

The ARC uses step-motor controlled Active Sway Bars, exerting a leveling force, not just re-engaging decoupled sway bars.

What I don't know is how the car decides to apply its swaybar forces. It seems to sense a high frequency suspension action, and permit that travel (like a pothole), but resists a slower acting movement, such as a cornering force, lean, lateral acceleration, rotation, or what?

It behaves much differently than the previous generation AMG63, which I thought was unacceptable. "Jittery" was kind - I thought it was more like "Dentist," and didn't stick on rough surfaces.
I like the ARC.

Im glad it evolved. What I would like to see is a direct comparison of E active and the AMG on some twisties.

Can’t give that comparison but the new suspension handles off camber roads & curves like a dream. There is no oversteer/understeer that I can notice even at speeds 30mph over posted. There is an occasional switchback going down hill that might be an exception. Obviously the vehicle weight is going to be a factor but it drives like it’s much lighter. I just returned from a long trip on two lane country roads through mountains. I found a few very sharp downhill (7 degree) switchbacks that I slowed down to 10-15 over as my passengers were uncomfortable with the steep drop off and lateral force.
The comfort of the AMG C mode is comparable to the GLE air suspension in S Mode…where I set mine. The C mode GLE is Boaty, IMO and rebound damping insufficient in any roller bump like a traffic Berm…it bottoms out with a thud.
As far as performance, I would like to see 0-30 numbers…I’m guessing the GLE 53 would outperform the the GLE 580 to 30. It feels like V8 torque but as some have said you don’t hear much exhaust sound inside unless the windows are down. Like many other cars, there is a slight lag downshifting after coasting at lower speeds. The engine turbo boost spools up instantly (with the electric compressor) but the TCU hesitates as it shifts down multiple gears.

Part of the confusion is Daimler/Mercedes has used the same or similar terms to describe different systems. In fact, here is a quote from 12/17 describing AMG Active Ride Control in the S65 Coupe that does use cameras:

"The S 65 Coupé's exclusive AMG ACTIVE RIDE CONTROL suspension prepares for bumps in the carriageway ahead before the vehicle drives over them. To do so, AMG ACTIVE RIDE CONTROL combines active suspension springing with continuously adjustable damping. The system precisely scans the condition of the road ahead with the help of a stereo camera to optimally adjust the damping of each individual wheel to the upcoming bumps ahead of time."