@newt @olmitch The reason why wayland is stricter is because on X11 you'd end up with unmanageable windows.

The Winamp/XMMS thing is a mess because the behavior is a hack where when snapped it behaves like a single window and when not it's 3+ entirely separated windows.
And I think it's pretty much the only program which does this, specially in modern age where it's been well… long dead.