Isn't the EngineerMode APK an MTK app? I have been involved in developing an Marshmallow MTK based phone in the past and in my experience their BSP's were pretty messy. I.e. a lot of cleaning up is necessary if you want a relatively quiet logcat and debugging APK's removed - even for user builds. Edit: I must have remembered wrong or I saw the EngineerMode on the QComm device we developed before our MTK based device.…
This is going to be a fun morning.