I've never been really happy with the way the original plugin handled the multiple device types. It wasn't very "smart" about the device creation process. Which got me thinking...
The state of the occupancy sensor in the Ecobee thermostats is kinda hidden. I fixed that for the remote sensors by making them true sensor devices, but that means the built in one in the Thermostat is odd man out. So I'm thinking about using the device group functionality to make a secondary Indigo sensor device grouped with the thermostat. I could also break out the Humidity sensor, but since that's already in the Thermostat UI I probably wouldn't.
I'm thinking of doing the same thing with the remote sensors, since they're tied directly to a thermostat and it would be easy to do. I can't think of any reason not to do the remote sensors if you're making a device for the thermostat.
I also want to do something about auto-naming the devices, since the server data already has the names that were assigned to each device.