Isso é o que eu encontrei para o FVWM, você pode especificar onde cada janela carrega com uma simples alteração de configuração , do FAQ:
7.3 How to start applications on a page or desk other than the current.
Use the 'StartsOnDesk' or 'StartsOnPage' style in your config:
Style Netscape* StartsOnPage 0 1
or
Style Netscape* StartsOnDesk 1
Any window with a title that begins with 'Netscape' will be placed on page 0 1 (desk 1). You will probably want to use these options
too:Style * RecaptureHonorsStartsOnPage, CaptureHonorsStartsOnPage
If you want to start applications on a different page in the
background without switching to this page, use the 'SkipMapping'
style:Style Netscape* StartsOnPage 0 1, SkipMapping
7.4 How to start applications on a page or desk other than the current without moving the viewport to the new page or desk.
Use the SkipMapping style:
Style Netscape* StartsOnPage 0 1, SkipMapping