ENTJ Laid back? No.
Outside of professional interests my ENTJ brother spends a lot of his spare time engaged in 'relaxing' things he enjoys like music, movies etc but he still doesn't appear to be relaxed while doing them, it's weird, he'll be listening to a song that he likes for example, and rather than just letting people listen he'll explain where they're from and who produced them etc, etc, etc. it's like he's still busy when he's perfectly relaxed, his mind never stops wanting to learn and teach. Not normally laid back.
Flexable? Not so much.
If he can logically see why something is the way he’s being told then he will continue the conversation, if the conversation is less logical he will get frustrated.