This data pack allows you to mark Fireworks Composer rooms to be limited to 1 player

• Limit rooms to only allow 1 player.
• Automatic Fireworks Composer chest reset when the player leaves.
• Room becomes available again when the player exits the game.

• Every room has a marked entrance and exit button, indicator block and a fireworks composer chest. (In spectator mode you should see armor stands at the buttons after marking them.)
• The indicator block closest to the entrance/exit buttons belongs to the same room.
• The entrance button closest to an exit button belongs to the same room.
• The exit button closest to an entrance button belongs to the same room.
• Players cannot enter/exit the rooms without using the buttons. Use "/tag <player> (add | remove) bcfwcpr_inside" to (un)mark players as being inside a room when they did not use the buttons.
• When a player stands the furthest away from the exit button, the closest exit button should be the one of that room.
• The fireworks composer nearest to the indicator belongs to the same room.
• No matter where the player is in a room, the closest fireworks composer should actually be in that room.

• You might want to make it look like the rooms have entrances. Use a sideways placed iron door that's always powered or place barrier in front of a wooden door to give it an entrance, while still preventing players from entering/exiting the room without using the buttons.
• You could add extra buttons to give players firework rockets or toggle lights.
• The data pack comes with a hopper filter. Stand inside a hopper and run "/function bertiecrafter:fwcpr/hopper/add_filter" to automatically delete anything that's not a firework rocket with at least one explosion from the hopper. Note that there cannot be any hoppers underneath the filtered hopper.