how do i keep pulled pork hot

Your roaster is too hot and it is continuing to cook the pork. Once cooked the meat can be held in a cambro before it is pulled. Once pulled it can be held at about 145 for safe serving.

If you make it the day before it should be rapidly chilled after the rest. Then gently heated when needed to a safe serving temperature with some apple juice.

When I cook for our VFW, I hold the pork in a cambro until we are ready to pull a pan for the serving line. Pull as needed to keep fresh and minimize the loss of moisture.

Cambro great for holding, steam table @145 works, try chicken stock vs apple juice much more neutral flavor, for reheating vac seal in big junks and use boiling water to warm up.