I agree it's a pretty key feature.
Of course, there are a lot of other problems with SMS. There's a reason other chat apps are so common, and a lot of it is key features like delivery confirmation and message length.
Perhaps Mudita should offer a cloud service that bridges various chat apps to their phone. If they take a privacy-first approach, it could be a really nice service.
Similarly, I would love to streaming music on this thing. Spotify runs on everything, so why not here?
Maybe I don't totally agree with their product vision though. I like the idea of a slimmed down, privacy-respecting phone. I just don't want to give up ALL the benefits of a smart phone. I would welcome a unified chat interface and a simplified Spotify app.
I would probably be willing to pay a subscription for secure backends to give me a streamlined, integrated experience.