Ok, I sort of get what you’re saying.
Why you’re having a problem, is you have written code for each box. You only need code for one box 
I will ( try ) to show how
Write your ONE box like this ( or similar )
Notice how all the variables I need can be set when I put the box in the map
I can put 3 boxes in the map and set the variables, so each box has it’s own sound/widget etc and already points to the next box
See, I’ve set box 1 knows which box to set ready next.
Is it making sense?