Playing 4 Videos synchronously.

[paralion]

I am looking for a functionality like SyncPlay, but just on 1 Computer.
I have 5 Screens, and want to output 4 different videos on the 4 screens simultanously and synchronously. That means, if I jump to e.g, second 47 on the timeline, all 4 videos should go to that point. The 5th screen by the way should show the play/pause buttons and the timeline.

Can that be done in Lua, or has it already been done?
Btw the function described in this video works, but only with maximum 2 videos. If I add more, they simply do not show.

Hope for help,
thanks, p.