We talked about this in the meantime, including in our Munich meetup. One thing we decided is that hosting a version of pontoon for the add-ons community will require support for Organizations in addition to supporting the file type. The work on either hasn’t been put on the short term roadmap.
There’s a good template in the bug I filed for Android’s strings.xml to see what the file-format support will take. I filed a placeholder for now, 'cause it’s Sunday.