The Touchbar in the 13" MBP counts as a display. So the Pro already runs 2 displays and can add a third. The same GPU+CPU is in the MBA which only runs 1 + 1 external display. It't not a limitation of GPU or whatever they want you to believe. This is pure market segmentation.
Does it? The touch bar is something like 2170x60px. That's a tiny fraction of the processing power and data bandwidth compared to an actual screen. In terms of raw pixel count, it's only about 2x as many pixels as my old Commodore 64 would push every frame. Each of those pixels is a lot deeper but it's still probably pretty much a rounding error compared to how much is being dealt with for the internal screen, never mind an external one.
(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 :)
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.
It looks to be at worst 10fps to my eyes. Which is also where animation really starts to shift from “moving drawings” to “fast slideshow” in my experience. So right on the border.
