How long have you been using this kamado?
Bought mine a year ago, thought the same as you, even asked a welder to cut me a steel disc out a bit bigger, he let me down. The plate is fine, used it week in week out and never had an issue, even when the rack is literally full of ribs/brisket/chicken.
If you've only just bought the kamado, use it for a month or 2 before deciding up swap the deflector out, honestly