Set a timeout for feeds that don't responded.
When a feeds doesn't response Podcast Addict seems to wait until it gets a response and then move on to the next podcast.
Set it so that if a feed doesn't response in a set time the app moves on to the next feed and then trys that feeds again at the end.
Of course there already are timeouts set on every connection. But some time a server is overloaded and can transfer data really slowly… In that case updating a podcast will take a while…