Chris,
Welcome aboard, I’ve had my 4 a little over 4 years and I only use it for large smokes. I just pulled 10 (8 of them were huge) pork butts this morning (108 lbs), 4 on top 2 racks and 2 on the third rack. I keep them as high in the smoker as possible. Your #’s certainly are realistic. Tomorrow I have 21 slabs of babyback ribs going on. I don’t anticipate any issues with that quantity at all. Good luck and enjoy your new cooker.
Mike