As I said, the broken base functionality is now working in rc5. I can replace regions with other regions when I doubleclick them, no matter how they were generated in the first place.
What is still inconsistent is the way, the italics are used in the node browser for said regions. If you create a region with the surround-by option in the context menu, it will be different then when you created them from the nodebrowser directly (i.e. not in italics).
Since this is merely cosmetic, I retagged this thread from “Bug” to “Feature”, in hope this gets rectified one day, even though it is non-critical.
PS: gif-recording with a Frame will not work, because the nodebrowser is not being captured.