That's a great fix for a common problem. I'd just add that a metal plate can warp over time with the heat cycles. A lot of pros use a piece of firebrick instead for the baffle, since it holds up better.
My uncle's metal baffle looked like a potato chip after one winter. He swapped it for firebrick and now it's been solid for five years. I guess some lessons are learned the hard, warped way. His shop doesn't smell like a campfire anymore either.