I like 190' for 24 hours put it on, when you want to eat it the next day. It is easier to slow it down and keep it warm, than speed it up.
If it is done in 20 hrs turn it off and leave it in til serving time it will stay plenty hot.
I just put a towel over the vent. I do fat side down on long cooks.
And you can sleep thru most of the cooking part and wont have any door openings either.