That's what I did. i.e. no extra diffuser in my mini. I also left the tamale strainer in and made sure the holes were not lined up with those drilled in the pot. Cooked 3-4 pork butts with no issues.
Smokemaster Offset*Hasty Bake*'WSM'00 Plum SSP*'69 Cado*'90 Red MT*WSM Mini*'73 WSJ