You're doing a great job, as you well know.
You mention in your video that you will be using a plastic hinge for your door. I used one from McMaster-Carr for a tongue box once. The description listed it as "UV resistant."
It failed after three years.
I replaced it with a hurricane hinge.
I don't mean to add a conundrum to your build. I understand how much thought and planning goes into these projects.
Tony