and someone posted this very cool cheese cassette art to the cassettefuturism community

That was also me :)

I haven’t been able to get it to work with Feeder

This is the URL that should work: https://iwse.artstation.com/rss

You can check it yourself opening in your browser. You should see “ugly code” like this, which the RSS reader knows how to read:

<?xml version=“1.0” encoding=“UTF-8”?>
<rss version=“2.0” xmlns:atom=“http://www.w3.org/2005/Atom” xmlns:content=“http://purl.org/rss/1.0/modules/content/”>
<channel>
<title>IWSE Zhang on ArtStation</title>