Hacking the MrCool WMK-19 USB Smart Controller

I installed a MrCool unit last summer that came with this chintzy little USB stick. This device allows your head unit to communicate with Wi-Fi, and it is trash. The reception is bad, the app that comes with it is bad, and it randomly decides to ignore your commands.

Has anyone looked into reverse engineering this device? I suspect that it’s just an HTTP API on one end and a serial interface on the other.