Followed your thread on slack recently and saw you went the modded APK route. I’m a long term app modding convert too 
This may help answer one of your other questions:
How to tell if you are in CE or FCC power mode using GO4
You may get different readings for the Phantom, but simply run a legit GO4 first, then your modded one, and compare the results? Please update that thread too 
Have you had a chance to test fly it yet?