You have to use the "wait" opcode - and the "close window" opcodes. And scripts. It's all got to be done manually for every single box, basically. Every box will have to use a "wait" - and if one is longer than another, you'll need to add a few different waits. One for 2 seconds, one for 3, and so on.
It's a colossal amount of work to do for the whole game and not really feasible.