I'm glad I found and read this thread. Just booked two spa cabins on Magic for January 2020. I can't believe how few cabins were left where I wanted. I usually do Lido but no rooms left side by side. I ended up booking two spa cabins on Panoramic. I thought the balcony partition would open but see now they connect with the cabins on the other sides. Started to go up a deck not realizing the balconies weren't covered. I guess I will keep watching to see if two cabins where the balcony divider will open later. The two I booked are connecting but it's two couples and prefer the balcony divider to be opened.
Anyway, thanks for the heads up on non-covered balconies on deck 12.