I guess if you want your content all slurped up and served as coming from AI with no backlinks.
Putting just the post intro in the feed and linking to the website feels like a safer approach, assume you have bot protections on the website, but that's a poor experience for people who want to read in their feed reader.
Edit:
Longer term, the approach might be - provide a separate RSS feed with full content but gated by a query parameter, then only give that URL to known-good consumers via email verification or patreon subscription, etc.
It would suck that people would have to pay more to consume content in their preferred way, but depending on your needs it might be a reasonable compromise.