The app allows you to use a number obtained from twilio or telnyx and you can use SMS, MMS, and calling features.
timconsidine has written a guide on LXC setup, and I think this would be a prod ready app.
Some features that are being worked on are

1. S3 backends for image storage
2. Admin and subuser accounts
3. in call dialpad
4. image purging customization

It has active development, and many folks are using this already.

The developer seems to be very receptive to collaboration, but doesn't have the bandwidth to package this themselves.

I'd be willing to work with someone to get this packaged into docker (never done that before).