I decided not to go with a faux heat shield for a number of reasons. But I still want to keep as much heat as I can from being absorbed into the firewall. Best thing to do is try to reflect the heat as best I can. Reflection is the opposite of absorption. Instead of being absorbed, some of the heat energy is bounced, or reflected off in the opposite direction. Vans firewall is made of high grade #304 stainless steel. This grade of steel will respond well to a polishing wheel with the right stainless buffing compound. I bought some WEILER stainless compound (1PBF4) and polishing wheel (5A724) from Grainger and though it was pretty messy, did a great job. Once polished. You are left with a slimy firewall, covered in compound and strings off the wheel. To do a final cleanup...I used Dawn for dishes. Dawn has a grease cutting agent in it and all came real clean.
Note to those who want to do this. Polish before you assemble anything. Would make it lots easier.