Am I missing something?
In order for him to make his sequence of escapes, he needs those devices. If there were just one escape situation, that might make sense. But there's a series of them.
-For him to see the need for the subsequent devices, he needs to have progressed through the sequence of escape situations, which means those subsequent challenges depended on his surviving the prior escape situations.
-So he would need to have escaped to the later situations, with the use of the helper articles from the envelope.
-So he would have foreseen his foreseeing the future and arranging to have those devices, and would have foreseen using them, up to a point.
-So some events of the story cannot happen until they've already happened.
____________________
The story is king.