Yes. It is the same process.
1: Vertically ‘stack’ the monitors in Windows - put one on top of the other in the virtual desktop;
2: You create an entry in one of the monitor config .lua files to define the DCS screen size which will be, if stacked vertically, the horizontal resolution of the biggest monitor and the vertical resolutions of both monitors combined (taking care to ‘remind’ DCS that it should only display the map and GUI on the top monitor;
3: Define the space that the sim is displayed (the viewport) to correspond to the position and size of the top monitor;
4: Define and position the space for the MFD outputs to be drawn as it corresponds to the bottom monitor;
Example: Top Monitor is 4k, bottom monitor is 1080p and it is centred below the top. Then the DCS resolution is 3840 x (2160 + 1080). The Viewport is set to 0,0 - 3840,2160 (meaning starting at 0,0 and extending across 3840 pixels and down 2160 pixels). This would be set as the Map and GUI resolution as well, otherwise it will stretch across both monitors. Then the MFDs assuming 300x300 fits within the ‘hole’ … lets assume that they are in the top corners of the lower monitor … MFD1 wound be set thus: as (3840-1920)/2,2161 - (3840-1920)/2 + 300, 2161 + 300. (meaning that if the 1080p monitor is centered on the bottom of the 4k monitor, it’s X position is the difference between the widths of the monitors, divided by two (so it is offset from the bottom left of the 4k monitor by 3840-1920)/2 pixels) and it’s Y position is 1 pixel lower than the 4k monitor).
I will see if I can dig up a diagram someone created.
Oh yeah. And you need to tinker with the kneeboard dimensions because it will, by default, try to use the full monitor.
I guess this is a cautionary tale. I bought 2 8inch monitors and build a 3d Printed frame to hole them behind the Thrustmaster MFDs. It was annoying to set up, but once it was set up it was amazing! … Until DCS was patched and i had to go and re-enter all the values in all the places again. I abandoned it within a few patches because of this.