Goal: go from this:

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  A->
=======
  B->
=======

=======

=======
    
=======
  <-A
=======
  <-B
=======

The movable block prevents the upper player from dropping down to the lower level.

The spikes prevent the upper player from coming down until after the lower player gets the parachute for him.

• players "share" items
• after you trigger the parachute, you can float down on spikes without problem
• this is the minimum height necessary to trigger the parachute

Last version confirmed in: Confirmed this works in v0.99.5.