The code is available here now: https://git.deusch.me/ubports/device-google-tegu
For now, this is more of an experiment than a real port, but there are instructions for flashing in the repo if you‘re brave.
A disclaimer: there’s AI generated code involved and I can’t vouch for the quality of the patches. Most notably, I had some keyboard crashes that are likely related to the pulseaudio code not properly cleaning up its resources. I didn’t have time to look into that yet.