That's a pretty cool DIY heat shield.
Since you had already wrapped the pieces you could also use Taylor Reflective Heat Tape. It goes for around $30 for 20ft.
It withstands 1100F continuous radiant heat and 500F direct contact.
Adhesive backed, easy to cut and easy to wrap. I used it on an intake tube years ago and it was still on after I sold the car.
Just a suggestion.