I am getting exactly the same results using the Homebridge-Nest plugin on homebridge running on a raspberry Pi. It’s nice to have the protects available in HA!
The room occupancy sensor works as you’d expect, but the names of the smoke and CO detector seem confusing. They just show up as binary sensors, and even in the entity name it doesn’t say they are smoke or CO.
Is there a way to fix this in the integration so the sensor type from homekit is properly represented in HA?