I really do not understand this. The 14" Macbook Pro (M1 Max) does support up to three external displays. What was the problem with these new Macbooks to not support at least two displays..
It's perfect segmentation, most people don't care, and those that do will pay.
(Hell, is the central GPU even running the touchbar, or is there a specialized display circuit just for it?)
That said, my reaction to this whole thread is pretty much "I guess multiple external monitors is a reason to upsell you to a Pro machine" so we agree on that point :)
But if it (as it actually is I suspect) a USB connected thing that refreshes very slowly, it's not a display at all.
And the MacBook Air can take a USB "monitor" for whatever that's worth.
Framerate's hard to determine from a youtube video of someone pointing a camera at it, single-stepping has some things seeming to move at the same framerate as the camera but redrawing the whole screen as the player moves around looks more like 1/3 of the camera's framerate to me.