Hello folks!
I forked ha-nest-protect and tried to add the cookie authentication.
Thank you @imick for the original code!
If someone wants to test it, it is here: GitHub - nicoinch/ha-nest-protect: Nest Protect integration for Home Assistant. This will allow you to integrate your smoke, heat, co and occupancy status real-time in HA.
I was able to test it with the cookie authentication method and 2 devices with battery. I was not able to test if it does not break the current refresh_token authentication.