I called a bunch of nurseuries, nursuries (?) PLANT PLACES that sold and dealt with paw paws. I was interested since you asked a very good question and it intrigued me. I love the fruit, but the tree flower smells awful.
After research and talking to folks - none of who have ever even thought about smoking with pawpaw- the consensus is NO.
If it stinks alive, it is worse dead. And pawpaw pretty much stinks alive, even though the fruit is wonderful.
Nicest place to talk to ishttp://www.shootingstarnursery.com/
they are about to burn a whole ****load of pawpaw that fell and they can tell you more on the smoke. Check in a few days.
My instinct tells me if it smells bad it is not good for smoking.
Good luck to you, and hope this helps!