18222:
About to do a big stuffing soon, what are some ways I can prepare to maximize my capacity?
Every day, I would eat until you are comfortably stuffed and then eat a bit more. These do not need to be high-calorie foods, as the focus is on capacity, not weight gain.
You should also be more active during these days because it will make you hungrier than normal. That way, you'll eat even more.
Don't be afraid to do liquid bloats as well.
I'm not sure how soon you'll be doing the stuffing, but I would do this at least a week or two before your stuffing.