I generally have a 3d viewport on my main monitor. I like to edit assets on my 2nd monitor. As of 4.7 all of the editors want to open in my main monitor docked to the main window per asset. I have to move each and every single one of them to the other monitor. They also have a tenancy to minimize the other assets.
In fact if any asset editor is open, it should default to docking with that. Which is how it worked before.