So user-made interiors connected to vanilla worldspaces are safe from the bug? That's something, at least.
I will update the entry about the bug to reflect that detail.
not entirely. sometimes it works if the worldspace is tamriel. it will not work if the worldspace is a child of tamriel (like whiterun, resulting in a blank screen, not always a CTD)
the bug only happens if your project is an esp. it is unaffected by projects entirely on an esm, so it is not at all related to just worldspaces. the bug is related to improper handling of memory on esp vs esm when transitioning from an interior to a worldspace.
the vanilla ones are "unaffected" because skyrim.esm is an esm not an esp, and not because the worldspace is tamreil (i hope that makes sense). i'm being as specific as possible.