fullscreen mode(s) in 10.11 and up (not MP-related)

[René J.V. Bertin]

Hi,

I've been doing some maintenance an an in-law's 2011 iMac, upgrading it from 10.11 to 10.13. At some point I noticed that the fullscreen widget was missing from the right corner of the window title bars, and that the "maximise" button apparently toggles fullscreen mode.

Which begs the question what happens on a multi-head set-up where you don't give a "Space" to each screen. Does putting a window/app in fullscreen mode still black out all other screens as it does on 10.9 (where you at least have the option to maximise the window instead)?

Sorry for the noise...
Thanks,

René