I have no problems running the released Cura 2.7.0 with a multi-monitor setup on Windows 10 Home 64 bit. I don't think it is a multi-monitor thing, but a multi-gpu thing. If the secondary display is running on a different GPU than the primary display, I can see how that would be an issue. However, this issue is an issue with the GUI framework, that is going to be hard for the Cura team to fix (and it would probably affect many more programs, like eg meshmixer)
The only issue is I only have one GPU. I have meshmixer and it runs on my second monitor just fine.