I also found out how to decode it, but not how to re-encode it.
Even decoded, it's an extremely deep XML doc that gives most free-tier AIs too much to deal with and they can't handle it (although that was months ago. Maybe they can handle it now) if you were to ask them to find anything in there.
I remember the code available from
salt.io and I believe it was under a license that made it okay to borrow from or use for other things (don't cite me on that though!), but in the past few years it has been removed from the public internet and I can't find it anywhere.