I just imported the modified RIS file you sent, Michael (and responded over email as below). The import seemed to go without a hitch, Sente found (obviously) lots of duplicates, and a post-import dialog indicated that, for any pair of duplicate refs, any information that had been missing from the existing copy had been harvested from the new copy. Perfect, just the behavior I'd want to see. But I've just had a look through the updated library, and not one of the references appears to have a DOI.

I then imported the modified RIS into my temporary library, and the DOIs appeared correctly. *Then* when I copied the temp library to my library, the DOIs came along too, supplementing the existing references as expected. The workaround involved exactly one extra action, so not a big deal, but I wouldn't have thought that step should be necessary.

I've tested a couple of imports; some are smooth, some not. E.g., in one case the newly updated ref included the DOI jxb/ern091 and the paper was tagged with DOI 10.1093/jxb/ern091, so they weren't recognized as being the same and a new copy of the reference was imported. (No idea whether the truncated DOI my ref had was Zotero's fault, or the journal's, or what, but there it is, and I'm sure it's not a unique issue in my library.) It would be really, really great if there were a chance for the user to intervene before that happens. I know there's a check-box in the Quick Add dialog for "Automatically link to obvious match" or something, and that it defaults to being checked, but when you're only importing one PDF and you have a reasonable internet connection, that option has barely appeared onscreen before the whole dialog disappears. The feature that Silvo suggested on the forum, forcing Sente to look in the library and ask permission before it ventures out to Google Scholar, would be a really nice option to have.

Thanks so much for your quick response, Michael. There may still be some kinks to work out, but I feel a lot better about diving into this project when I know TSS is paying this much attention to its users.