That's a good idea.
Looks like a broiler pan from a range.
Cajun Stacker, Cajun Bandit and WSM use similar heat deflectors as you probably know.
I think Cajun uses a pizza pan.
Hmmm....
A guy could go to the restaurant supply house, grab a pizza pan of the correct diameter and bolt it to the bottom of a kettle grate.
Probably would want to spacer it down a couple of inches so the smoke and goodness can circulate.
Line it with aluminum foil for easy clean up.
Do the Minion method for a nice long burn.