I use ModernMix all the time, and it is very useful. But there is one situation in which Windows 8.1 is overriding the "windowing" of apps by ModernMix and forcing the display into fullscreen mode: when you click on a link in the Mail app (and some others), a separate window opens for IE in ModernMix, but then Windows takes over and forces both windows into side-by-side mode. I find this mode very annoying, because it splits the screen 50:50 and the IE scales down to tiny little lettering. Moreover, when I exit IE, I'm returned to a fullscreen version of the MailApp, and ModernMix has effectively lost control over the window. I have to press F10 to window it again.
Is there any way for ModernMix to prevent this side-by-side snap feature when an App is windowed by ModernMix? Obviously preventing it should be optional, because some people might like it. It would be a great added value to MM if the option could be added!