Replace the inside door panel of my safe with metal panel I can customize

Recently purchased a Kodiak gun safe , KBX5933 model. Not really a fan of the fiber board door panel with the nylon pouches. It's just held on with 4 screws and sits down in a slot, which I've learned is fairly standard. I'm ware removing this will affect fire protection. That's not a concern to me.

I want to replace this with a metal piece, which would be more customizable for me. I plan on putting some magnetic mag holders and other things. The whole panel doesn't need to be metal, but I need some working room on it for magnetic items.

Who makes drop in replacements like this? Thanks for any points in the right direction.

( cross posted in r/guns as well )