interesting entertainment but has no probative value
I must have missed something... this is Pprune :-) Probative value isn't really what it's about, or so I thought.
But as far as the ADS-B / FR24 data is concerned, some common sense applies. The data is mostly self consistent and consistent with other known facts. There are a few apparent anomalies especially with heading and altitude, but they are obvious (and in the case of heading, could have been caused by the way it was flying in the last few seconds). It's extremely improbable that the smooth curve shown on the most recent plot would happen by chance.
Also, the aircraft was equipped for flight in the LAX Class B veil (and was within it until a minute or so before the crash), i.e. it was required to have a certified ADS-B installation. So yes, "
all those checks, flight tests, equipment installs were done and passed all the requirements" were required to have been done. It COULD have been done by a rogue avionics shop, and not have been flight tested, but it doesn't seem very likely.