I look forward to seeing your final setup.
I wish I could add a hide like that but the perches and rock wall would not allow the intrusion of an arboreal hide. Not unless I bought a taller cage. Currently this coastal is in a 2 foot high cage. She goes a bit over 6 feet and is eating 1 pound rabbits at 2.5 years old. I think I'd have to have a fairly larger box mounted which would just not work.
Seeing your animals feeding from those hides looks pretty interesting.
It has me tossing around some ideas.
Ultimately the size of the snake when full grown will factor in to what I can do.
How do you think a SD retic would take to your arboreal hides?