For the original poster (OP) to fill in:
Imagin one layout with several widgets inside scheduled on 5 players. Same content for all except one where you should show a special movie.
On this special movie, we can decide to tick “all” if we want to play it on all players or untick “all” to choose players in a list.
Like this, we can use the same layout for many players.
Do you think this is possible ?