A Biz jet is a Biz jet. It does not really matter if you are flying a CJ4 or a GV. The jump to a 747 is so big anyway what is the difference? I know they also ask about Atlantic crossing. Will they hire you if you have none? I am guessing Atlas trains on these things either way. You will be flying with a Senior Captain who can maybe help out too. It seems like no operators want to be the first one to train people anymore. They want you to be born with a GV type rating and 2000 hours in type. Supply in demand for sure.