Thank you for the feedback, everyone.
The FAQ says 5-6 minutes. My observations are more like 9-12 minutes. A cruising jetliner moves at about 8 miles/minute, so misleading the location by use of the term “Live” means the aircraft may be offset by 72-96 nautical miles instead of the FAQ derived value of 40-48 miles. It seems more accurate to say “Latest” except for those of you who are happy to live farther in the past while believing it is “Now”.
It would be easy to add timestamp annotations to the maps, since the track coordinates are already timestamped. One might just use the average timestamp of the set of the latest coordinates – discarding timestamps outside of a tolerance threshold.
I have also noticed that overlapping data sources, say from a terminal radar mixed with Center radar, are occasionally out of sequence and/or slightly out of alignment. This causes a jitter in the track. Not a big deal, but another feature enhancement might be better sorting/filtering algorithms.