Feedit review
I’d prepare the RSS notice while the site update is still in draft. Feedit gives me a place to write the entry and check its link, then publish the feed once the page is live. It runs on macOS Sonoma 14.6 or later.
Write the update while the page is still in draft
Import an existing RSS 2.0 feed from a file or URL. Add an item with a short title and the address of the page it’ll point to. Feedit can keep that item as a draft while you finish the page. Use its description preview to check how the summary and links look before marking it published.
I’d use Ulysses to finish the article and send it to WordPress as a draft. The Feedit entry is the shorter notice that tells feed readers what changed and where to read it.
Check the feed before you replace the public copy
Open Feedit’s validator and look at its errors and warnings. If you copied an old item as a starting point, check that the new entry has its own GUID. Feedit can flag duplicates and generate a new one for the new item. Once the destination page is live, mark the item published and write the feed to a local folder or publish to a WebDAV server you’ve set up.
Anabel’s take
For the first update, I’d write the feed to a local folder and open that copy in a feed reader. I’d check that the title is easy to scan and that the link takes me straight to the article. Then I’d replace the public feed.