Depends on your intended use. But the trade guns of the time were not particularly effective and used a lot more powder and lead than the rifles did. This is documented back to at least the 1750s.
The traders pushed SB trade guns on the natives because they sold a lot more powder and lead when smoothbores were used.
Many natives liked them. Like today some people like smoothbores some like rifles.
But few of the people who expound on the usefulness of the SB do not use them as they were used back in the day. They want to have jug chokes for example and modern shot it far more uniform and harder than shot of the 18th c. Modern wads change things a lot too. So shooting squirrels, for example, with an open choked 20 gauge with tow wadding and marginally round shot as would have been used back in the day borders on unethical. So they modernize their barrels and wads and shot and then think that how the gun performs is representative of how they performed back in the day.
NOW, there
are places where shooting squirrels with a rifle can be problematical even a very short ranged rifle like a small bore 32-36, ML with a RB so there are modern reasons for using a SB and then improving it. But its not strictly historically correct the way many use them.
Most bird hunting in American was done with large bore shotguns shooting rafts of waterfowl or punt guns for the same purpose. Wing shooting with a trade gun would be a PITA (as it is with any FL) due to variation in lock time. This was the driving force in speeding lock/uniforming lock time in FLs though lock improvements, vent and breech designs and was the reason the percussion system was invented. The Nock FL breech for example has proven to be the most uniform in speed in modern testing.
So if you intend to hunt flying birds you might find it problematical due to the lead being different for every shot. I am not a wing shooter but look to the variations on lock time in tests detailed on Larry Pletcher's
blackpowdermag.com site.
So decide what YOU want and go for it. If you want a SB you are not going to be happy with a rifle in any event. But you need to have info for any decision making.
Dan