I don't know how auto-update works, though, PII is solid identifier which should help retrieving article information from web.
So, I wish if auto-update feature would be able to recognize and utilize PII in the incomplete entries.
In my case, there are many entries with PII in title, like...
[Title] PII: 0146-6380(93)90045-D
(I don't know why all these entries being with PII as title, but might be related to import from Papers3 library without PDFs?)
FYI, a search with "0146-6380(93)90045-D" returns a good result in GScholar; a single exact article. OK!
While, with "PII: 0146-6380(93)90045-D", no matched result.
So, picking a raw string of PII number seems essential for this.