Their screening may now be equivalent to Pre Check, not sure anymore. They certainly are not screened like regular passengers. It is said that a pilot can always crash the plane, and I agree with that to a degree, but cabin crew have no such ability and their only means of attack would be to use some item already on the airplane or something they brought with them to the airplane.

Crew should be screened at no less of a standard that Pre Check including ETD swabs if that is being used.