This is the kind of bounty that can pay for a car (see the previous article web apps and car hacking).
It's also a great writeup that starts with an "I wonder" about hacking Google smart speakers, then walks through intercepting web traffic, looking at protobufs, dealing with OAuth, and Wi-Fi security. You don't have to be an expert on any of those topics to follow the techniques and the tools covered are useful in all sorts of situations, especially if you like to hack on IOT and smart home devices.
The gpsoauth library is at https://github.com/simon-weber/gpsoauth.
Find mitmproxy at https://mitmproxy.org (you can also install it from brew!).