Blerg steam is being slow...
In the meantime, really the natural way to work with windows (even in 3D space) is to use your mouse. Before you had to use an Xbox controller or keybindings, which worked but was pretty awkward.
Now you can move windows with your mouse! Specifically you can enter a "mouse control" mode via looking at a button below you for about a second (or by pressing ctrl-~), and this begins capturing anything you do with your mouse so programs no longer see those clicks and such happening.
Instead you have a little cursor that you can move similar to a mouse that orbits around the portion of space that you can see. When you left click with this cursor on any window it will focus on that window. When you hold right click on a window you can "drag" it around, then scroll in and out to push it in and out. When you aren't grabbing if you point your cursor at a window you can scroll to make that window bigger and smaller.
You can also click the middle mouse button (also Y on the Xbox controller) to open the "edit" bar below a window. This has:
- A slider that lets you change the target capture rate of that window
- A bar that shows you the name of that window
- A button to toggle the window in screen capture mode or in default render mode
- A button to minimize that window (this hides it, typically used to get a window out of the way that you don't want to see)
So I mean I guess on the bright side, since Steam is being slow you'll see these features in the first release! Which I think will help make this more usable for people.