Since Google STT isn't open source, I was wondering if there were plans to move to an open source project that is currently around for the STT engine while OpenSTT is in development.
No solid plans yet, but those are definitely options. Another good option would be Mozilla's Deep Speech project:
I'm doing all the internalization to Spanish using local CMU Sphinx as STT engine.
Waiting to pull request 614 to share the STT proxy class.
We are working on an open-source model based on Kaldi for French here: https://github.com/openpaas-ng/openpaas-sp5-lm-preparation