I've added a number of podcast RSS feeds to Volumio (actually it's a plugin to Volumio) which works fine. I tried to add yours, but it comes up saying there's an error parsing it so I can't add it.
I didn't compare Destination Linux RSS feed to yours. Maybe that might help to see what's different between yours and theirs. I'd really like to add yours to my feed.
Volumio is touted by Noah so I gave it a try. It is a bit less stable than I'd like but sometimes it works.
Anyway, what's different about your feed structure and theirs? Is it possible to make it work with Volumio?