This is a total wishlist, but it would be nice if (when given a URL that 404s) citoid attempted to pull something from archive.org instead of saying (more or less) "you can construct this manually".
|Open||None||T95388 Try to find link in archive.org for 520 page|
|Open||Mvolz||T115224 On URL submission, look up the archived page in the Internet Archive's index and add to the return data|
We actually currently do have partial metadata for "bad" links that return a 520 (404s only return for bad pmid/pmcid/doi). UX/VE team decided not to use the 520s in the extension because the 520s usually just put the url in the title and url field, but it's something I'd like to revisit soon. Looking for something in archive.org could help.