I've upgraded to the new Oxford 2024 version and saved (in custom-dict) the 2019 version.
It seemed that Kobo did went for a cheaper dict version: not only the entymology is missing (and sadly missed), but I also already encountered several words which are missing in the new 2024 version but *
are* present in the old 2019 version.
Well, I did too add the wikitionary (@xyclonei: great find

), so all in all I'm reasonable happy.