Well the short of the long is that he uses a disposable alum. pan to cook the meatloaf. He puts a total of 6 holes in the bottom corners and along the long line. That way, any grease would drain.
Here's his deal:
3 lb's of Ground Chuck
1 lb of sausage
1 cup of diced yellow onions
1 cup diced green bell peppers
1/4 cup wortershire sauce
Bread crumbs, mix half in and half later but he doesn't say how much
Adds some dry rub to it and mix. I would think he adds more of the bread crumbs to get the desired consistency.
Pack it in the pan with 6 holes and smoke at 250 degrees for an hour to an hour and a half. Then, he puts alum. foil on top and flips the meatloaf out and puts it back on the smoker on top of the foil. He's going for 160 internal. Then, he flips it back into the pan and puts a finishing sauce on it.
Not my recipe but that is essentially what his video says.
Hope that helps, let me know what you do, however you do it. Good luck