subtle

Nope, subtle doesn't reparent windows and there is in fact no reason to do that. The layout in subtle is a really loose set, the only relation between a view and a client is tagging and this is checked on every view update.

Reparenting windows would require following additional steps, when a window is visible on a certain view:

1. Resize the view toplevel window to the size of the current screen
2. Reparent the client window to the toplevel window
3. Handle (ignore here) the generated expose and crossing events

Probably sounds like not much overhead, but keep in mind this is just required because the developer of Java and Qt cannot understand following line from the ICCCM:

Clients must be aware that some window managers will reparent their top-level windows so that a window that was created as a child of the root will be displayed as a child of some window belonging to the window manager