I did a shoot where we lost a roll of shooting on the alexa mini. And I have heard a lot of people with similar tales.
Well no more (kind of) - using a program for mac os x - drivedx - https://binaryfruit.com/drivedx - let's you quickly see the reliability of a cfast cards.
Most solid state media either fails at the beginning of it's life or at the end - there is a significant white paper on this - so if you do a checkout from a gear rental house and you see some history of failure or that the card has been reformatted and seen a lot of use - maybe send that card back. What's it worth, right?