Just like the windows drove the size of the hexagon the elevator and hoist drive the roof design. So having the elevator cage made up will help in designing the roof line and hoist placement.
So this went better than I imagined. Two 2x6's are attached on edge to the hexagon post on the right. This is a temporary set-up just to test the proof of concept. The real ones will have a 2x4 stiffeners screwed to the back side forming a T for strength. Two pieces of garage door track are screwed to each 2x6. Garage door rollers are placed at the top and bottom of the cage. The hoist is squeezed into the soffit area just above the door. With 5 foot windows, and using one of them as a door there is a challenge in getting head clearance. This is solved by the elevator stopping 16 inches below the floor of the Treehouse. You can see the cement block in the bottom of the elevator. This represents the "step up" to get into the 5 foot high opening to the Treehouse. Likewise when exiting the Treehouse you step down and your head clears the top header. It works like a charm. Unless you are over 6 feet tall!
So next it will be on to finishing up the roof rafter attachments and placing some cable ties to strengthen up the roof system to hold the load of the roof sheathing. Tricky but doable.