Does a false bottom have to be stainless?

I'm a Brew-in-a-Bag brewer who is making a switch from the stovetop to an outdoor propane burner. Been reading up on the Aussie BiaB method and I definitely will try it for my next brew. This method calls for direct heat with the bag in the brewpot, which I have not tried before because of the potential for the nylon bag to melt/burn/rip.

While cleaning our house this past weekend, my wife and I found a pan roaster (similar to the interior of that was given to us as a gift. It's never been used and I'm sure it's not stainless. Could this work as a substitute for a false bottom to keep the bag directly off of where the flame hits the brewpot?

It looks like the spacing is too much anyway. The bag would slump to the bottom and touch the hot pot. You need a steaming basket.