I ended up writing a Powerwall app for the SmartThings hub that allows for monitoring and control of the Powerwall through SmartThings, and also allows you to fully leverage SmartThings to send mobile notifications and to command smart devices and Powerwall functions based on the current status of the Powerwall and other smart devices.
The app unfortunately requires your Tesla credentials since it communicates with the Tesla server instead of the gateway due to a combination of issues between the way SmartThings and the gateway currently deal with certificates. There was something similar out there for the Powerwall that communicated directly with the gateway a while ago, but it broke when Tesla added a self-signed certificate to the gateway web interface.
The app is available here:
https://darwinsden.com/powerwall and could use a beta tester or two if anyone is interested and has a SmartThings hub. I've been running it for a week now without issue, but definitely use at your own risk until it gets a little more testing.
The most useful part of the app for me right now is that it can be configured in the preferences to send mobile alerts when the battery level approaches the reserve or a user-defined percentage limit.
The app should alleviate the need to install a separate energy meter to your main panel when using the SmartThings demand management program:
The Demand Manager App for the SmartThings Hub - DarwinsDen.com, since SmartThings can now get all home usage and solar data from the Powerwall itself.