Great article and thanks for the soil recipes.
I had several Hoyas when I lived in Texas and they grew and bloomed profusely. I gave starts of them to everyone, they are easy to start, just put a good size piece (2-3 inches at least) in the dirt and they will readily start. The bloom is so beautiful and unlike anything else, they are so waxy they almost don't look real. The one I have now has the curly variegated leaves and doing well as a houseplant in KY.