I can confirm that the patcher.sh on Macintosh Garden restores the radio index on iTunes 10.6.3.
I have noticed that most of my podcasts can't update anymore. For some, I can see the title of the episodes but download fails. Others still sync fine, it seems to depend on where they are hosted e.g, "Hello World" is hosted at
https://feeds.buzzsprout.com/1746662.rss and still works fine while "Venganzas del Pasado" is hosted on
http://feeds.feedburner.com/VenganzasDelPasado I still see the episodes but download fails since 2024.