iOS player with offline playback capability?

I was all excited to recently discover Roon, but I think it has a show stopping issue. I searched the forums, and it appears there’s no way to play offline on iOS devices tracks that are stored on my Roon server (e.g. FLACs that live on my NAS). I’m not talking about streaming services; rather files that physically live on a NAS.

Did I just miss this in the Roon remote client for iOS, or does this feature still not exist in 2020? If not, I’ll have to go back to my Plex + Prism setup for offline playback.

It’s a well requested feature and on the roadmap for development but at the moment not available.