How can I edit an Atom RSS feed for correct post formatting?

Hi there, we’re creating a third party app for our magazine and will be feeding through our Shopify blog posts via the Atom RSS feed. Unfortunately the feed does not pull through with all assets correctly from the Shopify blog posts - for example, the lead image is missing and the spacing is a mess. My question is, is there a way we can edit the Atom feed to make sure our blog posts pull through looking correct with elements in the right place?

Also looking for a way to do this. It’s a ripple effect that’s affecting all my social channels.