"you can create 'two' levels on one layout so that one player can't enter region ('level') of another, and with canvas plugin you can simulate second camera - to separate 'levels' and player visualy."
but this time with capx
unbound scrolling set to yes, you can restrict camera with sprites only or combine layout size and sprites that are separators...
edit: tilebackground doesn't work with canvas plugin when WebGL is ON !!!