I was initially worried given the lack of documentation, plus Sonoff stating in their FAQ SONOFF NSPanel Pro Version Update Information and FAQ - SONOFF Official that this is unsupported… Well, good news, it turns out to be actually unlocked and trivial to run whatever app you like.
So far, I connected via USB, ran various adb commands, including side loading and running various apk’s including Device Info and HA Companion. After updating to the latest version, I noticed I was also able to connect adb via wifi as well.
I was not able to sign in HA companion yet, not sure why.
Next I plan to try to get HA Companion to login and load at startup, I wonder if there is a way to setup the credentials via adb so I can script the entire setup from within HA similar to the AndroidTV integration.