It is not the take off voltage that is critical for a partially discharged battery. The voltage when flying can be much lower when flying, especially on used batteries when they are are not still warm from flying. The internal resistance of LiPos increases at lower temperatures, at lower battery voltages, with age and after much useage. How you store batteries can also cause batteries to deteriorate faster. However taking off with a fully charged battery insures that the battery is warm when it gets to the lower voltagesI read the entire thread and I'm looking at the log, 15.837V, 3.8V/cell at TO. That, by every definition in electrical engineering theory, is nominal for a 15.2 "rated" battery. You can continue to try and make that the argument, but that isn't the argument.
The net-net of the entire thread should be, always take off with a 100% charged battery. DJI is clear on that.