Joetisserie for KJ's, and BGE

I haven't. I would think the flare ups from the melted fat would cause some issues.

Id be more worried about the juices putting out the lump dead center of the cook.

I almost always have a deflector on which would keep all those issues mentioned from being one.

I agree with some sort of deflector but if you look at their pics, the meat is directly over the coals.

Put a small foil pan in the middle and coals on the outside.

The drippings wont put the fire out, they hit the lump and produce smoke, same principle as a coffin style brick bbq pit. It should actually impart more flavor.