I think part of the challenge might be related to adapter use. On my MBP, I connect either through HDMI or a displayport->VGA adapter. My MBP exhibits the beha

I think part of the challenge might be related to adapter use. On my MBP, I connect either through HDMI or a displayport->VGA adapter. My MBP exhibits the behavior you mention if the displays are on difference adapters, but it doesn't recognize different displays plugged into the same port/adapter (e.g. all HDMI displays are the same to it, all VGA displays are the same to it). My Surface only has a minidisplayport port, and I suspect the adapter I'm using isn't fancy enough to tell the Surface that the attached displays are in fact different. Definitely a bummer though. and 4k support in general on Windows 10 (and macOS, but less so) is a little iffy. Issues really start to show when remoting into a session on a device hooked up to a 4k monitor.