I copied your recipe and will give it a try.
I usually make one from a recipe from the Good Housekeeping cookbook from years ago. I use a cast iron frying pan too; I really like your idea of draining the fat part way through.
Another thing a cast iron pan is great for is soda bread, I think that’s the key to it.
I believe you are correct WRT the soda bread. Cast iron skillets are great for even heat displacement, that is probably the key to good soda bread.
When I can’t bring myself to pay the same amount or more for thinly sliced bacon and end up using thick sliced, I par cook the bacon in the cast iron skillet and leave a little of the bacon fat in the pan prior to placing the meatloaf in there.
Last time I cubed the bacon and par cooked it, then incorporated it into the meatloaf instead of putting it on the top. It is a real pain to cut through the thick sliced cooked bacon and the tender meatloaf underneath without destroying it.