The VideoLAN Forums

From everything I have read, running VLC on multiple displays in any version newer than 1.2 doesn't work. Is that correct or is there a way to display the same video on multiple displays in version 2.2.4?

I can not give you a definitive answer on that, but my advice is to use an OS native feature (like screen mirroring) if feasible. I have done so as needed in the past with success. It is a bit of an annoyance to turn it on and get it set up right, but it works. Whenever possible I always seek solutions outside of VLC- for all its great aspects & features, stability, reliability, support & documentation are not often among them.

There is a video mirroring feature in VLC, but by default, it cannot put it windows to fullscreen. If you use macOS native fullscreen mode though, you can put the windows to fullscreen on different spaces, by using the OS controls.