When you open an OPML file, it should preserve the title element of the file. Same when you save the file.
Lots of old code in here, hard to follow, but I believe I found and fixed the problems. It was mostly confusion, because op.xmlToOutline, the core code, does preserve the title.
There's a new pref, user.prefs.flPreserveOpmlWindowTitle, that disables the change. It defaults true. Setting it false will restore the old behavior.
To get the new parts, choose Update opml.root from the File menu in the OPML Editor.