Have you guys considering using the Weblate platform instead of Transifex? I don’t feel that comfortable using proprietary platforms to contribute to open-source software.
I haven't personally considered anything else, but I have worked with decentralised translations using a Git repository for a different project.
Ubuntu MATE were already using Transifex when I joined the team, and it's features keep things simple and free (in terms of money) for the project which is nice. While the account and UI is proprietary, the standards are open (PO/POT files = GNU gettext). The same can be said for GitHub - a proprietary service but it's utilising Git, and no person/company can take away the freedom to use GPL licensed code.
I do NOT want to give away my personal data, including my translations, to proprietary platforms, to contribute to their TM. There is precedent of data misuse in platforms like Crowdin and Transifex, whereby they take user's translations without respecting the license set by each project (and that is not to mention the pervasive use of web analytics to spy on users). You should know better, honestly.