I recently watched Elizabeth Taylor’s “Cleopatra”. At the end of it, I wanted to know what was told accurately and what wasn’t. This was a mistake. What started as one Wikipedia page turned into a “rabbit hole”. I spent hours, quite literally, reading about Ancient Rome, the lives of Julius Caesar and Marc Antony, and eventually ended with the ancestry of Cleopatra and Marc Antony’s children.
All of this to say: Yes, a factual-accuracy-o-meter would be useful for “based on real events” movies. Then again, if we had one, I’d have nothing to do next time I am recovering from knee surgery.