MST Hub + DP Switch - Can they work?

[Schro]

I'm currently on a quest to get my desktop and my Surface Pro 3 to happily share my 3 screen setup on my desk. I have a trio of Dell U2412m, thus have a DP port on each monitor. My desktop rig is currently hooked up through 3x DVI connections and the Surface Pro 3 connects through DP on a MST Hub allowing all 3 screens to be used. I have a separate USB switch that handles changing over the various peripherals. So, The annoying part is that to switch between machines, I have to go into the menu of each of the 3 monitors to change the input that they're using which is a bit of a pain, so I'd like to make my life easier by adding a DP switch in-line before the hub. The problem I've had with this idea is that not a single DP switch (or DP capable KVM switch) that I've looked at is willing to say that it'll pass through a MST screen - they all will give a maximum resolution of 2560x1440 (and some will state 4k).

So, given the lack of clarity, I emailed the support group for the two most promising switches (based on description) - Startech and SIIG. Startech replied that their DP switch would only work for a single screen (meaning, I'd need 3 switches, so why bother) and SIIG didn't seem to understand the question, and ultimately said that they didn't test my device with my product, but can guarantee the resolution I'm looking for (which is 1920x1200) even though they won't say anything about 3x 1920x1200 passing through (even though I specifically asked that question). In theory, if the switch supports the full 5.8Gbps link, I would imagine all 3 screens should pass through the switch just fine.....

That being said, has anyone else tried to set up a similar setup and actually had success? Or will I just need to start buying DP 1.2 switches until something works?

If nothing else, I suppose I could make my own by hollowing out one of these....