Searching Google I only found speculation about it.
Has anyone confirmed that the Surface Pro supports DisplayPort 1.2 and can handle daisy chaining 2 external DisplayPort monitors as extended desktops?
I hooked mine up to a NEC PA271W (27 inch) and the resolution was fantastic. I could not believe how sharp the image was. I had the option to mirror the monitors or extend the desktop. I did not see a 3 monitor option but then I only had one external monitor connected. The bad news is that you cannot change the font size on a monitor basis. The Surface is set at 150% which looked huge on my 27". But when I changed to 100% both monitors changed and I could barely read the surface display.
To use Displayport 1.2, both the computer graphics card and all the monitors must support the standard. You will not be able to test it unless you have Displayport 1.2 monitors.
There must be some place that has the specs of the Displayport in the Surface Pro.
Detailed specs seem unusually difficult to find.