Catfish have these strings: _Update Search Index… Save \%s\ as… Searching… Suggest chaning "…" to "...": _Update Search Index... Save \%s\ as... Searching... So "..." is uses consistently in all Xfce translations.
Sean Davis referenced this bugreport in commit fa082506c73e2ed233f0abb5fa5138e7a3c87c20 Change "…" to "..." for consistency (bug #15407) https://git.xfce.org/apps/catfish/commit?id=fa082506c73e2ed233f0abb5fa5138e7a3c87c20
Thanks for the suggestion! Applied above, and the translation templates on Transifex should update shortly.