The following reads a little like the shell game that it is.
So I discovered when you 'Float View to Window' you can sometimes 'lose' a view if/when you create a new document. In the example video attached I began with a red artboard, then created a new document with a green artboard. I then float this green artboard document to window. I then created a new document with a blue artboard that was spawned in the floated window without any tabs visible. At this point it is no longer possible to find the green artboard document. I then went on to create a yellow artboard document that was also spawned in the floated window, but this time it was presented in a tab along with the blue artboard window. The green artboard is still missing.
I then deleted the yellow artboard, which returned the floated window to a non-tabbed window with only the blue artboard window visible. I then deleted the blue artboard window and suddenly the green artboard window was once again in the floated window.
Anyway, the idea of a floated view is interesting, but at this point it's not really useable as there's no way to manage documents reliably within it. I'm also not sure new documents should always be created in the floated view, especially if I've focused on the original app window when selecting the new document command.
Personally, I see the floated view as potentially useful as a reference window, or a document pasteboard where you copy/paste objects to and from as you work on other documents. As it stands I really can't see any other use for floated views–especially as they often end up floating above all of the tools and panels required to work, and they are definitely not a replacement for separated mode.
Maybe I'm just using wrong (the docs don't say much)?
FloatViewIssues.mp4