PSDLE uses, from what I have known, the relevant APIs to get the Entitlement data which are different for the old store/download list and the new story/Library view. For the new store I don't recall them returning the download/play status, however I do not have a PS4 or PS5 to test with.

What headers are you referring to?

I refer to the fields psdle is offering, like isDownloadable, isActive etc.
Not sure whether this can be feasibly done, but when clicking on "Downloads" in the browser, all downloaded games appear on one page. I was mildly successful with copying the text to an editor and converting this to a csv format, but it was a bit tedious...

So the links are:
https://library.playstation.com/recently-played
https://library.playstation.com/downloads

I think the "title-id" field found in the page source is similar across the 3 pages, so the plugin could grab all 3 pages and list them in one big list.