TL;DR: I am waiting to hear back from Purism on how to proceed with Chatty integration, and I don’t know the status of mmsd-tng in PureOS.
To be clear, I am not a Purism/Pine64/related employee, so I do not set priorities for them.
What I can tell you is mmsd-tng is in the pipeline for the Debian repo, it is in Mobian Unstable, and it is in PostmarketOS. I do not know its status for PureOS.
I can also tell you that I have a branch for chatty that supports (backend) MMS support, but still needs UI integration. But since I am not a developer for Chatty, I am waiting to hear back on how to proceed on (since I do not want to make changes then have to revert/change them again). You can see my MR here:
And my branch here:
Additionally, that branch is dependent on this MR to be merged into Chatty: