Oh, I see. By “doesn’t work” I thought they (and you) just meant it still hits the server even though you have a model downloaded.

Yeah, on a spotty mobile connection, most services tend to be optimistic that it’s better to wait than to assume your internet is down. iOS online/offline callback is very optimistic, probably because for most services, trying something in a degraded 20b/s conn is better than giving up and going “sorry, no internet.” (Funnily enough, the iOS App Store gives up way too soon)

So I agree. I think the right thing to do is to do an instant translation with the local model, when available. Maybe a cherry on top is to see if the server has a better translation in the background.