I don't know for sure but I was told if I used a 100 lb cylinder I needed a regulator there to reduce pressure before it hits the regulator for the smoker or a gas grill. As I said I'm not 100% sure of this but it was a gas employee that told me this.
I'm not sure you where told the truth.
It should be the same pressure just more volume.
I'm far from a smoke master ......but I do deal with propane on a daily basis...being a plumber.
Can't hurt to double check though..............good luck.