I have a three monitor setup, with two monitors driven directly by Ubuntu 12.04 for a total workspace/desktop area of 3840x1200¹. I usually work with 5 virtual workspaces, often more if I work on several projects in parallel. I typically have at least 15 browser windows open (mostly Firefox-nightly, but also standard 12.04 Firefox and Chrome).
Whenever the browsers need to restart as the result of an update (c.q. crash), or need to start after a login, the browser windows come back to the original positions, but all are on the same workspace. After that I have to tediously move at least 80% of the windows to other workspaces².
Neither Firefox nor Chrome save the extra EWMH information that is needed for restoration to the original workspace. I have read unresolved bug reports dating from 4-5 years ago about that.
It seems that, at least a few years back, KDE managed workspaces as large offsets (wider than the screen(s) width), which allowed the browser to restore to the correct workspace. But this no longer seems to be the case (deducted from a bug report, not from personal experience).
Is there is a workspace/desktop-manager that doesn't have this restore-all-to-one-workspace behaviour with Firefox and Chrome (preferably on for Ubuntu or Linux Mint)?
Or is there another way to enhance Firefox and Chrome (e.g. add-on) to enforce this behaviour?
Mine is not a fixed layout, where Browser X on workspace Y always opens to a specific URL. The restoring function gives me the windows, positions and URLs exactly the way I want them. They "just" need to be on the correct workspace.
¹ A third 1200x1920 monitor is on a separate machine with
x2vnc used to share a single mouse and keyboard. That nicely keeps my reading material like man pages and documentation available (in portrait mode).
² All U&L stuff is on workspace 3. I normally leave the machine running, and stay logged in, for weeks at a time, one of the reasons for that being the restoration of the various windows.